then, um, if it has like nothing to do with the engine and AFR and fuel trims, why did it trip the codes like it did?

Because it was a vacuum leak on the engine. :p

LOL, now why didn't I think of that? It's truely amazing how interrelated all these gremlins are with our cars, isnt it? Gee, I wonder why my car seems to respond so incredibly negatively to electrical gremilns? (and cue the red car jokes...)

Glad you found the problem; those vac lines tend to either melt or snap like twigs, sometimes under the corrugated tubing...dang gremlins!

well, at about 300 miles, the same 4 codes were thrown again. No melted lines, O2 seems good, but I did find this wire disconnected. It's on the same cable as the O2 sensor. identification help, please?



The ABS connector in question is the one up and right from the engine lift bracket. Thanks yall.

EGR maybe? I can't see the plug in the EGR from that pic, kinda blurry.

Can you get a clearer shot maybe?

EDIT:

Ok, I just took a lamp out to the car and took a look at my wiring harness.

From what I could tell, that is the main wiring harness. It has every front sensor plug (MAF, MAP, etc.) as well as all the back ones (O2, EGR, Oil Level, etc.)

Off the same branching as the O2 sensor, I couldn't find any plug close enough to be that other than the EGR. However, I can see now that you EGR is still plugged in and also, it is a yellow plug cap.

The only yellow plug caps I could comfirm were the MAP, TPS, and Coolant Temp sensors.

However, none of those are all that close to where your plug is. What year is your car? Mine is a 98.

I'm kinda confused right now, I wish I could get a layout of the whole wiring harness...

Lemme go try.

I have that SAME wire on my car that goes to nothing....

holy almost triple post batman! sorry, forum hiccup

Here's the EGR up front, with the connector barely visibile:



Here's the connector in hand with a good clear shot of the EGR and quite a few other connections:



Thanks, Mike, for contacting me outside the forum, as long as another GT reports the same loose connector and has no issues with it, Im good.

So that means that that connector is ruled out. What else could it be? If everyone else is stumped, I'll be callin the good wrench tomorrow and see what he says.

Rich, I had the same question on my engine swap. That is the only plug I couldn't find a hole for when I was wiring stuff up. I think it turns out to be a hookup for air-injected vehicles to reduce emissions for Cali. (PS, I'm running an L36 harness.)

AH. so that definitely has nothing to do with my codes, then? Awesome.

So...
now what?

Yep, gonna call the wrench tomorrow.

Do me a favor. Grab some ether, carb cleaner, or brake cleaner. Start the engine. While running spray it around the EGR area. See if you hear the rpms go up.

dont have any of that. I was jsut talkin to my Dad. He had said to check the air filter. Well, the K&N was certainly filthy (thankfully I have a spare paper filter laying around for K&N cleanings). He also suggested PVC and EGR. What I will do, right after posting this, I WILL go and visually/physically inspect. True, not as reliable as spraying combustibles around the fuel system, but hopefully eyes and fingers can show me SOMETHING.

I'm wondering if this is an electrical gremlin at work.

Both P0131 and P0137 are low voltage sensor codes.

I wonder if maybe there is a short in the harness somewhere or possibly it's getting too hot and raising the impactity of the wire...