ThosL Posted August 2, 2012 Share Posted August 2, 2012 My '99 Subaru with a 2.2 engine (transplant) recently started stuttering. I went to Advance auto parts they used their diagnostic tool without anything clear coming up. I checked the wires and then plugs and noticed one of the plugs had rattled loose and the plug screw tip had come off even though the plug wire was still attached. I replaced three of the four plugs with Quatros by Bosche, the same that had been in there, the fourth plug, driver's side rear, is hard to reach. The stuttering or jerking subsided but has come back. Slight loss of power and annoying. I put a container of Lucas gas treatment in with some premium gas--no difference in the 200 miles or so. What is the next possibility? Thanks for any recommendations. Link to comment Share on other sites More sharing options...
bstone Posted August 2, 2012 Share Posted August 2, 2012 Was there a Check Engine Light? If so what was the code? Link to comment Share on other sites More sharing options...
ThosL Posted August 2, 2012 Author Share Posted August 2, 2012 Check engine light is on because engine was switched out, so no way to really address that though I spent $$$ trying to. Either it is electrical or fuel issue, probably the former. Link to comment Share on other sites More sharing options...
bstone Posted August 2, 2012 Share Posted August 2, 2012 Again, what were the codes? There is no reason that the CEL should be on even if the engine was swapped. I swapped the engine in my outback and I don't have a CEL. Link to comment Share on other sites More sharing options...
ThosL Posted August 2, 2012 Author Share Posted August 2, 2012 Maf or map sensor; has been changed 3x, so that is not it. Cat converter; again irrelevant for a stuttering engine. Link to comment Share on other sites More sharing options...
ThosL Posted August 2, 2012 Author Share Posted August 2, 2012 Problem could be coin, a $70 or so part; I doubt it is plugs or wires since they are recently changed. Link to comment Share on other sites More sharing options...
bstone Posted August 2, 2012 Share Posted August 2, 2012 Maf or map sensor; has been changed 3x, so that is not it. Cat converter; again irrelevant for a stuttering engine. Incorrect. A plugged converter can definitely cause the engine to stutter. You're probably getting a P0420 code, which means the O2 sensor is likely bad. Which one is it pointing to? Link to comment Share on other sites More sharing options...
CoupedUpSubie Posted August 2, 2012 Share Posted August 2, 2012 Quatros by bosch? Never heard of them but I believe your talking about the Platinum +4 plugs. They have 4 ground electrodes on them. My car started running like absolute crap with those and the good old cheap NGK's went back in. The problem with the Bosch plugs is that they are designed for engines where the plugs enter straight into the cylinder. If you examine the plugs you will notice half of it has some carbon build up after 1000 miles or so. Double check connections to crank and cam sensors and clean your MAF and throttle body. Be sure to use the cleaners made for each. Link to comment Share on other sites More sharing options...
bstone Posted August 2, 2012 Share Posted August 2, 2012 You must absolutely only use NGK (aka OE) plugs and OE wires. No exceptions. If you try to substitute something else then you will misfire. Link to comment Share on other sites More sharing options...
ThosL Posted August 2, 2012 Author Share Posted August 2, 2012 That sounds more like religion than mechanics. No one I know believes that and I have spoken to many mechanics and parts shops. Link to comment Share on other sites More sharing options...
bstone Posted August 2, 2012 Share Posted August 2, 2012 That sounds more like religion than mechanics. No one I know believes that and I have spoken to many mechanics and parts shops. You're kidding, right? Are you here to ask for help and receive free advice or are you here to jerk us around? Link to comment Share on other sites More sharing options...
CoupedUpSubie Posted August 3, 2012 Share Posted August 3, 2012 You don't have to run OE plugs and wires. I run napa wires with NGK plugs. It is true that subaru engines like the regular old NGK's and as long as you have a good set of wires then you are all set. I found the reason the Bosch plugs don't perform as well is due to a decrease in combustion leaving more carbon. Also you should notice a drop in fuel mileage and power on regular or what you normally run. Link to comment Share on other sites More sharing options...
ThosL Posted August 3, 2012 Author Share Posted August 3, 2012 You're kidding, right? Are you here to ask for help and receive free advice or are you here to jerk us around? Stop bullying members on this forum!!! If you want to turn Subaru ownership into a religion then start your own Subaru church. I have been a Subaru owner since 1990. Link to comment Share on other sites More sharing options...
Fairtax4me Posted August 3, 2012 Share Posted August 3, 2012 Bosch Platinums work great in some cars, and in some other cars they don't work at all. The fact that you have had them in your car for some amount of miles (you didn't say how old the plugs were), says that they must be at least OK, even if not ideal. I prefer to stick with what the manufacturer recommends, since they generally do alot of research to find the best spark plug for their application. But here the fact is, you only changed 3. That one old spark plug could be the one causing the trouble. You definitely want to get that one changed ASAP before chasing other issues. CEL codes may point to something. If you can post the exact codes, we might be able to narrow it down, or at least help you get rid of the codes. Link to comment Share on other sites More sharing options...
CoupedUpSubie Posted August 3, 2012 Share Posted August 3, 2012 A tip for the last plug that has the windshield washer tank in the way. Pop the tank out for a minute. It is two bolts, two plugs and two hoses. Just be careful with the hoses. I would change out the plugs to NGK's and replace your 02 sensors. O2 sensors will do many wierd things to these cars. Fairtax- he said the codes relate to MAF and the cat. Link to comment Share on other sites More sharing options...
bstone Posted August 3, 2012 Share Posted August 3, 2012 Stop bullying members on this forum!!! If you want to turn Subaru ownership into a religion then start your own Subaru church. I have been a Subaru owner since 1990. Dude, you're coming to a Subaru forum where we have a collective hundreds of years of experience working with Subarus. Some of us are mechanics and work in actual garages and specialize in Subarus. If you don't like the advice that we give, such as only using NGK or OE plugs, then that's fine but don't insult us by calling it "religion". We're here for free so you had better be respectful of our time. Link to comment Share on other sites More sharing options...
ThosL Posted August 3, 2012 Author Share Posted August 3, 2012 Bosch platinums are great plugs. Now you can argue that NGKs are better, but the argument that you must use the OE parts and you must follow the dealer recommendations will saddle the average owner with costs way beyond what he would pay with a competant mechanic or doing things on his own properly. The reason I bristle with the absolutist talk is because I have seen it in many areas where people put themselves out as experts. Look I have done everything in my power to get my car in functional condition. There are grey areas and then there are black and white areas. Bosch vs. NGK is a grey area. They are pre-gapped and high quality generally. One thing I have not seen mentioned is how the tips of spark plugs can vibrate off in time which happened to me. Where did the tip go? I sure hope it didn't slip into the engine when I pulled out the old plug to put in the replacement. But spark plug tips that are not sealed on the plug can be a cause of problems. When I asked a while back about an overheating problem, it was a stuck thermostat, something no one but a passerby suggested but this does happen even with OE parts; the good samaritan who stopped by suggested that and he was right. Link to comment Share on other sites More sharing options...
bstone Posted August 3, 2012 Share Posted August 3, 2012 Every time I have a Subaru that is misfiring it is always because of the wrong plugs or wrong wires. Put in NGK or OE plugs and OE wires and the misfire goes away permanently. This isn't the case with one or two Subarus that I've worked on but hundreds. Link to comment Share on other sites More sharing options...
CoupedUpSubie Posted August 3, 2012 Share Posted August 3, 2012 There are many documented cases of bosch platinum plugs losing the ground electrode while in a subaru engine. Honestly if you go to any subaru forum and ask what plug everyone finds works the best for them they will say NGK. This is due to personal experience using other plugs. What bstone was saying is that using OE wires and NGK plugs is a sure way to eliminate the possibility of that being the problem. Buying bosch plugs is twice the money compare to NGK plugs and in my case NGK plugs resulted in gaining 2 mpg over the bosch plugs. NAPA wires will cost you about $20. Have you tried cleaning the MAF and throttle body? If you go to get plugs and wires be sure to grab cleaner for them. Read the cans as you can royally screw things up if you don't. If cleaning and plugs and wires don't help then my money is on your front 02 sensor Link to comment Share on other sites More sharing options...
fishy Posted August 3, 2012 Share Posted August 3, 2012 There are many documented cases of bosch platinum plugs losing the ground electrode while in a subaru engine. I don't remember for sure but I think it was a Bosch plug I had in a Lumina once that lost a piece of electrode. The plugs were less than a year old and the result was mad misfiring, stutters, hesitation, and a bonkers reading from the o2 sensor (because of that cylinder puking raw gas through the exhaust). I always inspect and/or replace plugs in a car with any of those driveability type symptoms first thing. With hondas and subarus you're looking at $15 for a set of 4 NGKs that they love. If your problem turns out to NOT be the plugs (and wires) then congratulations: you've just invested very little time and money into a partial tuneup most cars are overdue for anyway. That said: I switched out the knock sensor in my 98 Impreza because it was hesitating and bucking under throttle too. those are about $15 shipped from ebay for cheapie no-name ones that work fine. They're also a common failure point in subarus. They're also ALSO a quick easy thing to switch out. Link to comment Share on other sites More sharing options...
WoodsWagon Posted August 3, 2012 Share Posted August 3, 2012 The cheap NGK's do work best in these for whatever reason. The DOHC 2.5l's had to have OEM wires, but the other engines work fine with quality aftermarket ones, like the blue NGK's. The codes you listed have nothing to do with the engine swap. They may have shown up when the swap was done, but if it was done right they wouldn't be there. The MAP code could be the vacuum hoses going from the intake to the passenger side strut tower hooked up wrong. The p0420 is usually the 02 sensors and a front sensor going bad can cause driveablity issues without setting an 02 sensor code. Link to comment Share on other sites More sharing options...
ShawnW Posted August 4, 2012 Share Posted August 4, 2012 Bosch platinums are great plugs. Now you can argue that NGKs are better, but the argument that you must use the OE parts and you must follow the dealer recommendations will saddle the average owner with costs way beyond what he would pay with a competant mechanic or doing things on his own properly. The reason I bristle with the absolutist talk is because I have seen it in many areas where people put themselves out as experts. Look I have done everything in my power to get my car in functional condition. There are grey areas and then there are black and white areas. Bosch vs. NGK is a grey area. They are pre-gapped and high quality generally. One thing I have not seen mentioned is how the tips of spark plugs can vibrate off in time which happened to me. Where did the tip go? I sure hope it didn't slip into the engine when I pulled out the old plug to put in the replacement. But spark plug tips that are not sealed on the plug can be a cause of problems. When I asked a while back about an overheating problem, it was a stuck thermostat, something no one but a passerby suggested but this does happen even with OE parts; the good samaritan who stopped by suggested that and he was right. I run a Subaru shop. Ive tried just about everything. I have had customers ask me to put a specific brand in and then later on they aren't happy. Autolite, Champion and Bosch seem to be less reliable in my experience. Furthermore, the Subaru genuine part isn't only available at Subaru. From my Supplier the original OEM plug for your car is actually cheaper than anything else offered. Its $2 each and it has always worked with no comebacks. Why argue with something that works for me (Former Subaru master technician), and the many members here that I have seen make unpaid endorsements for the product. I have beeh here since 1998 and I have seen this topic brought up over a hundred times in this and the older generation forums with the same resulting answer. I also like the Denso plugs but they are usually more expensive. I run these in the 96-99 Outbacks and 4 cam turbo engines only. Anything else gets the Standard or Iridium NGK. Link to comment Share on other sites More sharing options...
Fairtax4me Posted August 4, 2012 Share Posted August 4, 2012 Bosch platinums are great plugs. Now you can argue that NGKs are better, but the argument that you must use the OE parts and you must follow the dealer recommendations will saddle the average owner with costs way beyond what he would pay with a competant mechanic or doing things on his own properly. The reason I bristle with the absolutist talk is because I have seen it in many areas where people put themselves out as experts. Look I have done everything in my power to get my car in functional condition. Bosch plugs are great plugs, nothing wrong with them. But some people don't have the same experience with them that you may have. The reason everyone here recommends OE plugs (which are just NGK in a Subaru box) is that they have an almost 100% success rate for curing spark plug related misfires. It's not that there aren't other plugs out there that will work, it's that the OE plug is almost guaranteed to work without problems, whereas other brands of plugs can be hit or miss. There are so many factors that determine whether a certain plug works; air density, temperature, fuel quality, and combine those with any number of mechanical reasons such as cylinder wear, high / low compression, oil consumption, ignition system voltage, and most of all the type of ignition system. The wasted spark system on Subarus fires two plugs at the same time. But the polarity of the spark is reversed on one plug. Rather than jumping from the center pin to the ground electrode, the spark goes the other way, which will build excess heat on the ground electrode and wear it away instead of wearing the center pin. With this style ignition system one worn out spark plug and one brand new one connected to the same coil can make a big difference in the way the spark jumps the gap of the plugs. Fairtax- he said the codes relate to MAF and the cat. MAF or MAP, which could be something as simple as a vacuum leak, but it helps to know the CODE so we know what the ECU is looking for but isn't finding. P0420 could be related to the MAP/MAF code. Or could just need an antifouler on the rear sensor. Link to comment Share on other sites More sharing options...
ThosL Posted August 4, 2012 Author Share Posted August 4, 2012 I was able to get J and J to check it out on short notice. They said it was the hard to reach plug that was bad also one of the plug wires. Once they replaced the wires and the plug it starting running like a top. Thanks for the feedback here. Link to comment Share on other sites More sharing options...
ThosL Posted August 13, 2012 Author Share Posted August 13, 2012 A Vermont parts store gave me more info. on NGK vs. Bosch. Next time I will go with the best of the former Link to comment Share on other sites More sharing options...
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