I had a similar issue that ran like yours is now...
It was the MAF!...

Thats why I suggested it...
Hope it works for you!

 

Thanks! My husband will be testing that on his lunch break today. *crossing fingers*

 

Ok, he unhooked the MAF. It's running like a dream!!!! Hooked it back up, crappy, unplugged it again, running perfectly!!! Question: is it safe for him to drive with the MAF hooked up?

 

Do you mean safe to drive without the MAF plugged in?

The car will run very rich, and it's not good to run that way for an extended period of time, but you can do it.

 

So now our mechanic is telling us it "might not be a bad MAF, might be a bad wire leading to it or the computer isn't interpreting it properly." Do you think that has merit? I think we should just swap the MAF, but ...

 

Since you aren't sending any signals to the PCM from the MAF it could be wiring or the sensor.

But they should be able to tell if it's the wiring easily with a multimeter I would think.

 

Thanks, I can't tell you how much we appreciate all the help on this!

 

And my husband would like me to ask, since it has been suggested by a few people, if his washing of the engine could have damaged wires/the computer. Now we're hearing to check the o2 sensor near an exhaust leak we have. (resonator) We've had that leak for awhile (keeps getting worse) so hadn't considered it. Swapping out tps now. (again, free exchange just to rule it out)

 

I dont know if I would:

Run it without the Maf unhooked like mike said (chibi)..
What worked for me..Is I replaced the Maf sensor....and my problem was solved...

Even thought there on the expensive side(MAF)....That mechanic...might be tryn to tap ya for more cash...The question is...do you trust him?

Or if your husband can do the test mike suggested to check the wireing...I would go with that first...
But Im sideing with a new MAF sensor...Let us know what fixed it pls...
and good luck! Hope this helped...
also..I would get the exhaust fixed and then see if the O2 code clears...
If not replace the O2 and your fuel mileage will also increase again...after fixing the exhaust leak...