friendly_jacek

Your post is very refreshing. People usually boast about record MPG but do not disclose how slow they go. City: 16-18, Hwy 23-25 (70-75 MPG) or 20-22 (80-90 MPG).

Thanks, timing advance seems OK: 15 degree on idle and 30-40 cruising.

Couple of posts above, there is a post how this DOES NOT work in Subaru. Newer Subs (2000 and up) use wideband A/F ratio and not conventional O2 sensor. This could be a problem for some scanners and interfaces. I use BR-3 from http://obddiagnostics.com/ and it works fine in my 2000 subaru and 2003 toyota.

Does anyone with OBD2 scanner/interface or digital sensor can tell me their engine temp? Mine is 180F while driving on hwy (75MPH) and 187F or so idling during summer (AC off). I am troubleshooting my poor MPG and exploring all possibilities (I covered all common things, you can search for my posts). Maybe the thermostat is set on a low-normal end and a 10F bump up would improve MPG? Thanks!!!

What oil did you use and what intevals (miles AND months). This is the first time I'm hearing about sludge in subaru.

Replace 4. Lots of discussion on it in the past threads.

You are probably correct, I have 4EAT and the sound is coming somewhere from the tranny rather than engine.

That was an excellent idea. I personally don't use CC in hilly are. Some people claim you get worst MPG with CC in these circumstances (frequent downshifts, high RPM). I believe it.

Some cars, I think toyota including, store a code and ilumminate MIL only after 2 separate trips with the same malfunction. Maybe subaru is one of them. The blinking MIL signifies a condition potentially damaging to emission componets as opposed to more benign malfunction. Frequent misfires or super rich condition would belong to that category. Maybe Texan is correct that overfilling can cause this, but I would not try to rechallange. On the other hand, you can check the plugs if you didn't drive too much afterwards.

Unscrew the bolts!

Does anyone know if the Nokians WR is rated as low rolling resistance tire. Alternatively, any experiences with gaining/loosing MPG with this tire?

So, we have votes for TPS, fuel pump, and ABS. It doesn't really matter. I guess I can ask my wife to press the pedal and I will check myself what is making the noise. Can someone try and tell me if it can be duplicated in another subaru? Thanks!

Is it normal? It happens everytime I try. The buzzing sound is somewhere from engine and stops when I release the pedal. Can anyone with 2000-2004 SOHV 2.5L H4 confirm if that noise is normal? Additional observations: with engine off, OBD2 interface registers MAP 29.5 inHg (normal at sea level) but 25 RPM, 2% engine load, and 0.4 lb/min air flow (i know, it should be 0 for all of them). After the pedal manuver, the pressure jumps to 30.1, 25 RPM persists, but the other values go to 0. WTF? Am I overanalyzing?

I'm glad you got it fixed. However, you mechanic is incorrect on the leak issue. First, 4-cylinder has only bank one sensors. Bank one does not point to any heads but to the engine as a whole. Silicates present in antifreeze are very toxic to O2 sensors, that explains why it died in only several months. Get oil tested for water, sodium, and glycol for confirmation.

I'm in the same camp. 16-18 MPG in city only. But 23-25 MPG hwy. 2000 Legacy wagon. Service by the book, 56000 miles on it now. I tried a lot of things. I keep 40 PSI in tires, all synthetic fluids, checked all sensors via OBD2, all nominal and readings are real (ie corresponding to ambient conditions). O2 sensors work well; replaced front anyhow, no change. The only consistent abnormalities I detected was fuel pressure above nominal and negative long term fuel trim. Replaced the fuel regulator to find no change in the pressure or fuel trim! My hypothesis is that some subaru fuel regulators are defective and replacing with subaru part doesn't guarantee anything. One of these days I will try aftermarket variable pressure fuel regulator, but now I will just scrach my head in disbelieve.

I did, #11 above.

That was what I always thought before buying a boat. My 2003 bayliner has black positive and yellow ground wires (from factory). Go figure.

So, what was the problem before the mod? Hesitation, uneven idle, poor MPG, poor acceleration?. I'm trying to see what to expect before starting on this mod. BTW, thanks for sharing this.

FYI, My legacy has EJ251, I just double checked that since I ordered some parts online.

Vanguard, Is this what you are looking for: http://www.ngkspark.com.au/tech_index.htm?http://www.ngkspark.com.au/pages/tech_info_oxygen_sensors_index.htm The pictures are toward the bottom of the page Jacek

OK, I used ramps and after 2 trips to auto parts stores for sensor wrench (only compact one with offset worked) and liberal application of CRC 6-56 I got it off. It was very easy to unscrew once I had access and grip. 40000 miles on it and changed in desperate attempt to improve MPG. The sensor is soothy but no deposits whatsoever.

defective spark plug? loose plug wire? Random event? But not coolant additive, that is for sure!

ditto, good towing car, especially in slippery conditions.

You can have chronic and diffucult to diagnose misfire codes from things as banal as dirty MAF sensor or vacuum leak. You just need a good diagnostician. Unfortunately, dealers are notorious on swaping parts only and not using brains. Again, did anyone check for vacuum leaks? With one side misfiring, it could be intake/gasket leaking. One should also look at the O2 sensors signals and fuel trims to see the patterns. Better yet, get yourself a good OBD2 scanner, download free subaru service manuals and read up on electronics. http://www.obdii.com/ is a good resource. I recommend BR-3 interface. My experience with both Subaru and Toyota dealers is that they brake more things than fix things.

I will be changing mine this weekend, and will let you know. Could it be ash from burning oil or gas additives?