Pesky Trouble Codes won't go away!

[Starkapopolis]

OK, for the past year I've had an engine light. At first it was code 41- A/F learning control. I replaced the MAF and things improved. Then it came back and was revving and idleing on it's own. A few months ago it started a new trick - going down the interstate holding steady at a high speed (50-80) it would start to run very rough and would only get smooth when I accelerated, pushing the engine into a higher gear. A mechanic checked it out and said everything was firing perfectly and he thought it was the o2 sensor. Replaced that from the jy. Slight improvement. You guys suggested it was the ECU. I got a good used one of those at the jy and immediatly everything went away - for about 3 days. Now the problems are back. I'm getting three codes right now: 41 - a/f learning control, 32 - o2 sensor, and 14 - injector 1 misfiring or emitting a bad signal.

 

The used parts came off a similar car with only 60K so I figured they were still good. When the new ECU went in it was like a new car but now we're back to the drawing board. Is this a doozy for the dealer or does anyone have a clue what I can do next?

 

91 Legacy LS automatic. 125K mi.

 

Thanks in advance.

Brian

[mattocs]

Did you reset the ecu? (unhook the battery for 30 minutes)

[Legacy777]

Hmm....with your problems, I'd suspect the ECU and/or possibly the MAF, but those items have been replaced.

 

It's possible you have a wiring problem somewhere.

 

Try pulling fuse 14 (EGI/TCU) for 30 minutes, and see how the car runs.

[Starkapopolis]

Thanks for the ideas. Since the ECU is recently replaced, I didn't think I'd need to reset it, but I'll try unhooking the battery.

 

Also, I just happen to have a 3rd MAF and will try that one as well. Then pull the fuse and let you know if any of that works.

 

If none of that works, I'll consider turning to a mechanic.

 

Rough on the road,

thanks,

Brian

[Cougar]

Since changing The ECU made things clear up, for a short time at least, I would tend to think this problem may be due to a bad connection near the ECU. Your moving things around made things better for awhile at least.

[Starkapopolis]

Since changing The ECU made things clear up, for a short time at least, I would tend to think this problem may be due to a bad connection near the ECU. Your moving things around made things better for awhile at least.

 

 

I disconnected the battery while at work and drove it home at the end of the day. the engine light was off for half the drive (15 min) but quickly popped back up. I agree with Glen's guess on the wiring. Since it was sharp as a top with the new ecu but then registered some trouble codes, it leads me to believe i should stop replacing parts and start looking for a good electrician in Arizona. Preferably Tucson, but elsewhere would be okay. any leads?

 

Brian

[Cougar]

It sounds like the O2 sensor is bad. You could replace it and then see what happens.

[Legacy777]

When the CEL came back on, did you pull the codes again? Are you getting the same codes?

[Starkapopolis]

only code coming up now is 14 - fuel inj 1

 

still running rough and hard shift (Auto trannie) while accelerating.

[Cougar]

That injector may be bad, but check the wiring to it to see if there is a problem with it. You could also swap injectors to prove it is the injector itself.

[Starkapopolis]

I like the idea of swapping injectors, though I hope it's a loose wire somewhere. Anyone have ez diretions on where the injectors are and how to swap them?

[Legacy777]

It's a pain to try and pull injectors. If you pull the electrical connector on the injector, does the car run any worse?

 

Injectors are the red things

http://www.main.experiencetherave.com:8080/subaru/images/injectors/DCP_2492.JPG

[Cougar]

It's a pain to try and pull injectors. If you pull the electrical connector on the injector, does the car run any worse?

 

Injectors are the red things

http://www.main.experiencetherave.com:8080/subaru/images/injectors/DCP_2492.JPG

 

Good thought Josh. Pulling the connector off will do about the same thing as swapping the injectors.

[beezer]

I have had a similiar proplem. The CEL would be on, and when driving it would hurk and jerk along. It would lose power and then regain power if I hit the gas. It might be good for 3 days or 2 minutes it wasn't predictable. The codes were always the same, not the same as yours, but always the same.

 

The culprit...........spark plug wires.

 

Sometimes when a problem occurs with something that isn't attached to a sensor it will trip off something that is. Check out the little stupid things, sometimes they are the problem.

 

Maybe check all the connections, clean them, some dielectric grease if necessary. It is strange a little bump might just jar something enough to create a bad connection.

 

Just a stab in the dark.

[Starkapopolis]

Thanks all. Enough people have mentioned that these long-standing problems are usually something small like a loose wire. I'll try pulling a wire off an injector and then hunt for anything loose elsewhere.

 

dreaming of a "smoooth operator",

 

brian