i have an 86 firebird 2.8 a/t with od. i little after i got the car the SES light showed up and i took it to autozone to get the code pulled. kicked out a code 32 for egr so i bought a new valve. i couldnt get the new valve put on as i didnt have many tools and the back bolt is a little tricky to get to. well eventually the car started bucking under heavy acceleration so i brought it in to have the valve replaced and that didnt help so they checked and my plug wire were arcing and the MAF was shot. the code 32 was still showing up occassionally. now i just put on a new K&N filter and sprayed out the throttle body and all of a sudden im getting a code 34 for the MAF. i also had the cat replaced after hearing it rattling. should i replace the MAF or could something else be the root cause such as bad ECM or what?

 

i also have an audible exhaust leak in the manifold somewhere and get the distinct smell like im running rich

 

If you have an exhaust leak, then yes, it's a good possibility you are running rich. Any exhaust leaks before the O2 sensor will pull in air and fool the sensor into thinking the engine has less gas going in than it really does. You might want to go back in and make sure the EGR valve and piping is nice and tight...

As for the code 34, try disconnecting the sensor before you do anything. If the engine runs better (the ECM defaults to a different air/fuel mix chart since it doesn't know how much air is coming in, BTW this will set a code 34), then you need to do the following...

First, remove the air filter or air cleaner housing and unplug the relay that is hidden behind it. That is the one and only MAF relay. Switch this relay with the one for the fuel pump (IIRC it has a tan/white wire coming in to it) since they are the same. If the MAF works (you did reconnect it after the above test, right?) then the relay is bad. Leave the fuel pump relay in place and go get another one from the parts store to plug into the fuel pump relay harness connector.

Second, if switching the relays doesn't work, then reconnect everything and reset the ECM. The easy way to do this is to pull out the connector on the frame rail next to the air cleaner with a red and an orange wire coming into it. This is the ECM constant power fuse, and the one next to it IIRC is the one for the MAF sensor. Also check to see if the MAF fuse is blown. Anyways, pull out the ECM constant power fuse from the connector for 10-15 seconds and put it back in. Now, restart the engine. When the engine warms up, tap on the MAF with a couple of fingers. If the engine hesitates or otherwise reacts, the MAF is bad or it has a loose/broken connector.

 

The SES light usually doesnt come on for like 5-10 minutes, maybe even more. i think i was able to eliminate the code 34, a section of the air duct came loose a little.

could the exhaust leak be causing the code 32 for the egr. it doesnt run bad once the light is triggered

 

Check all the vacuum lines going to the EGR area. You know the plastic one that hooks right into the EGR? Follow it backwards. It splits and goes into an "EGR Diagnostic Switch" and the "EGR Solenoid". Solenoid looks like a can, the EGR diag looks like a fat square.

Operation goes like this: Computer turns on EGR. Solenoid allows vacuum to go to the EGR -and- the diagnostic switch. If the switch doesn't see vacuum, the light comes on.

So that means if you have a crack ANYWHERE in those plastic lines, the service engine light will come on with the EGR code. You can use 5/16th windshield washer hose to replace those plastic vacuum lines... or, you can even use the hose to splice a cracked section of line back together.

Oh and the comptuer will only try to turn on EGR when all of these happen:
1. engine is warmed up
2. car is at road speed (higher than 45 mph)
3. engine is at low RPM
Basically that means you're crusing (not racing) on a highway. That could be why it takes so long for the light to come on.

 

code 034

if you post a search about code the site will only search if you use a three digit code. like i did. also, take a look at this thread. it might give you some additional insight,

 

well i eliminated the 34 by securing up the air ducting and cleared my codes. droves about 30 miles yesterday, mostly on open road, and didnt get any SES light. i dont know if i will get another code later on for the egr tho. i also have a slight issue after the car has been driven a few miles and is warmed up when i come to a stop the rpms drop real low, a little below 500, then come back to about 550 or 600. could the egr not be closing properly causing that to happen?