I'm in the process of fixing up my car. When I bought it the car ran like crap and I've been slowly fixing it since day one. So far I've just gotten better performance, but no mileage increase. I've replaced the MAP, TPS, and Right oxygen sensor. All of the brakes have new pads on top of that (it has a real bad habit of burning through the pads on the driver side compared to the passenger side, but I'll worry about that later).

So, I've got the same thing that a lot of you guys have got. Stumble all the time (except WOT sometimes), especially under slight acceleration and speeds around town driving. The car is throwing an EGR code 32 and right oxygen sensor lean code. I don't think there's anything wrong with the right oxygen sensor since it's new. I'm getting my first payday from my new job this Friday and hope to fix the car this weekend. I'm planning on buying new plugs and wires (maybe somebody can give me a hint on a good sale going on for wires), but I'm afraid the egr being messed up will just foul out the plugs. So how much will the EGR mess up my mileage, cause I'm getting about 11mpg with grandpaw driving. I saw on the Advance website that there are two different versions of the EGR valve, so how would I know which one to get? I'm planning buying pretty much everything it takes to fix the engine this weekend so any help would be appreciated.

 

Here's a copy of the e-mail I just sent you after reviewing your data log of the car idling for a few minutes. The log does not look good with reference to the right O2 sensor. It is reading excessively low, and the PCM is not correcting for that problem. Almost like "learning" is disabled in the PCM>

 

So what should I do to fix the problem? You listed all kinds of stuff that isn't right and I'm hoping that one thing is throwing the rest of it off. Should I reset the BLM? Would it even be worth changing anything until I figure this out?

 

Anybody else can chip in if you have an idea or have had this problem before yourself. I'll listen to other people too.

 

I've never seen a log like yours. The PCM is not responding to a major lean condition. You can't just look at a log like that and pick out one thing and say "replace it".

You have to figure out why the left side is always pouring in extra fuel with the BLM's. Since with the new right side O2 sensor, and a 128BLM its running very lean (irrespective of the fact the PCM is not trying to correct the problem) it would appear to confirm that its a true lean condition, and not a "false lean". Fuel pressure could be low, air could be getting into the engine some way other than the IAC.

Add to that the fact that the IAC is maxed out and you have multiple problems to resolve. The IAC may be opening up because the engine is idling so poorly that its having trouble keeping it idling at all. But if its running poorly because its running too lean, the fact the IAC valve opens full is only making it run leaner.

Have you ever done a data log at anything other than idle, because there's really not a lot more to be learned looking at several minutes of idle?

 

How is your idle? This sounds like what my friend's car did when his PCM died. He had new SLP headers and apparently the dealership said they cooked the PCM.

Maybe switch the fuel injectors from the right side to the left side. See if the problem follows them.

Make sure your O2 sensor wires are not burned anywhere as well.

 

That was where I was going to suggest. Unplug both O2 sensors and see how the car runs. That will take the O2's out of the equation. Make sure they both read ~.450V so you know they are not burned through somewhere and drive the car.

 

I can't really do any scans with anything other than idle cause my buddies laptop won't accept my cable. I have the USB adapter, but his laptop always tries to install it like it's a printer or something when we plug it in and then Freescan won't recognize it.

My car idles pretty well. It's missing a little cause I need to replace the plugs and wires (was hoping that was what was causing the mileage problem). I was planning on buying them this weekend and changing them, but the car doesn't struggle to idle or anything most of the time. If I start doing a lot of stop and go trips and sometimes when it sits overnight sometimes it will stuggle to stay alive, but that's not a regular thing. It just idles really low and all of that, but after a few minutes it's fine.

Is there any way I can test the PCM to see if it's fried? That would make sense I guess since everytime I replace something it says is messed up it decides something else is broke.

The oxygen sensor wires aren't burnt anywhere.


So, what what I can tell you can you tell me anything else?

 

See if the mileage increases and the car doesn't stumble with the O2's unplugged. Just a quick check.

 

Ok, I ran it with both the oxygen sensors unplugged to town and back just to try it out and here's the differences:

Still stumbles, just slightly less.
It smells really, really rich compared to usual.
It would backfire when it shifted, but does not at all with the oxygen sensors unplugged.

 

Richer? It should have made it run leaner. It almost seems like you would have to have a vacuum leak of some sort. I'm sorry that the O2's didn't fix the problem, but now you can rule them out. It's something else.

 

I've been without internet access from Friday till today, but I've been running without the o2 sensors since then. I've also changed the oil and put in fuel injector cleaner.

So it's running a whole lot better performance wise.
It's getting better gas mileage by about 50% more than what it was.
It doesn't backfire near as much as it use to when it shifts (usually only on 5L plus rpms).

Sorry it took so long to respond.

 

So, are you gong to leave the O2's unhooked? Maybe you could borrow someone's O2's to see if that is what is wrong with your car. It could be the left one acting up and causing all kinds of problems.

 

I ran it some more yesterday, and it doesn't actually do better with the gas mileage, it just takes longer up toward full compared to how it use to be. It use to take 50 miles from 3/4 of a tank to 1/4 of a tank, now it just has all the mileage up to 3/4 of a tank and takes 10 miles to go from 3/4 of a tank to 1/4. So I'm guessing the o2 sensors aren't really affecting my gas mileage. It is running better though. So I guess the o2's aren't the problem affecting the gas mileage.

Is there anything that could affect the EGR to make it give up a code? Cause I'm going to go out and buy a new EGR valve here probably next week if that is messed up.