Ok, so my car is an 89 GTA, with the TPI 305, 5 speed. When it warms up, it idles rough and stalls. It is also running rich, as you can smell unburnt gas when its running. The check engine light goes on, so when I read the codes I get a Code 33 and Code 45. According to my Haynes manual 33 is a MAF or MAP sensor error, and 45 is rich exhaust.

I've tried to do some searching on MAF sensors, but from what I've read most people get an Code 34... I've also found out they are ridiculously expensive too! I was hoping someone would have some suggestions to help me out... I'm also wondering if the MAF sensor malfunction (if thats what it actually is) is also causing the rich exhaust.... ideas?

 

a faulty MAF would cause the O2 sensor to sense a rich condition.

Unplug your MAF sensor, and see if the car runs any better.

 

It took me a while to get around to trying this... its end of the semester so school and exams have kept me busy... not to mention that when I tried to start the car the other day the battery was dead.... ANYWAYS....

I started the car this morning with the sensor connected. It seemed to run well for about 10 minutes, and then the RPMs started fluctuating and then it stalled. With the MAF disconnected, the check engine light went on right away (gave me a code 33 again), and the RPMs continued to fluctuate. Didn't really notice too much of a difference running it with or without the MAF connected. As the car heated up it tended to run a little worse. I reconnected the MAF sensor again, and started the car and it gave me a code 33 again.

As a sidenote, I noticed I have a small exhaust leak... there is a small crack in the weld between the exhaust system and the CAT... I will be patching this up... just wondering if this has anything to do with the problem.

Any suggestions would be greatly appreciated....

 

your exhaust leak can very well be causing your problems. The O2 thinks it's running too lean because of the exhaust leak, and so it sends extra fuel in, then you get a rough idle, and the O2 goes 'Oh ****" and throws a code.

 

Why would it throw a MAF code tho? That's weird... well, I'll try to get that crack patched over and see if it makes any difference. Sure would be nice be thats all I need to fix the problem... altho I doubt it... its rarely that easy and cheap to fix any automotive problem! ha ha

 

So wait a sec.. i just re-read it lol... It runs the same w/ the MAF sensor plugged in, or unplugged?

You should get that exhaust leak fixed anyways, it'll screw up your mileage

 

I did some searching and a post made reference to a troubleshooting chart for code 33... so i'm going to do some more searching and see if I can find it.... maybe that will help me out...

I have exams next week so I won't have much spare time... but the week after I hope to work more on the car....