Hi Guys,

I have a 94 LT1 that I recently got from my dad that has done nothing but give me trouble. It was reading code 13 & 24. I replaced the oxygen sensor and the purge solenoid and cleared the tubing & hoses as it was full of burnt gas. I couldnt get to the Vapor Canister as I ran out of time.

The car was running terrible prior to the new parts and clearing of the lines and then began running good and only showed a code 13.

I spoke with GM about the Vapor Canister affecting the oxygen sensor and they said it could if it is trying to purge and cannot. I checked the lines and they were full of crap again. I replaced the Vapor Filter and Purge Valve cleared the lines again and now the computer is reading 13, 24 and now 37. I have more issues then when I started!

I tested the EGR and it seems to be working correctly.

One last thing - I tried to reset the codes and the ECM will not reset. Tries it twice and the codes just stay there. Bad ECM?

Can somebody please help make sense of this and steer me in the right direction. Any suggestions other then take it to the dealer would be greatly appreciated!

Thank you,
Aaron

 

What do you mean "burnt gas"? If you are seeing pieces of black bits in the lines, that is charcoal from the vapor canister and more than likely the purge valve is bad sucking charcoal through the vacuum lines.

 

Thanks for the reply. I really have no idea how this system works, so charcoal it is! I replaced the canister and before that I had replaced the purge valve. The lines had the charcoal it is again when I replaced the canister... Do you think I will need to replace the purge valve again?

I just don't understand why I have more code now then when I started and why the ECM will not reset?

 

Ok, so I went back through everything and cleaned all the connections I could find and the ecm finally cleared. I took the car for a 10 mile ride and no engine light came on. I thought I had it fixed and later that night took the wife out to dinner and the light pops on after abot 20 min of driving. I replaced the oxygen sensor again and still no change.

Can sombody give me arun down on things to check that would affect the sensor?

 

what you should look into doin before replaceing them is makin sure ur pcv valve is good or just replace, clean ur air filter, make sure ur fuel injectors are clean. also look into cleanin all the built up carbon out your engine,

 

Thanks for the response. In the process of elimination I did clean the air filter, and replaced the PCV valve (Purge Control Valve) Although the line built up again after it was replaced. Maybe I should use the lifetime warranty and get a new one?

I'm new to this type of mechanics so bare with me. Question - How do I clean out all the carbon from my engine?

Thanks,
Aaron

 

i got mine done at the dealership, its like 80-90 bucks and it cleans everything. i recommended it

 

What he is talking about, I'm sure, is the GM top end cleaner. You can almost get the same effect by running Seafoam through the brake booster line. One thing though, you better know what your doing before you try it. You can hydrolock a motor if you're not careful.

To clear the codes, one way is to disconnect the battery for a few minutes and this should clear the codes. What you are doing is the "shotgun approach". Load a wad of money and parts and aim towards the car and hope something sticks. That's not the economically fiscal way of doing it. What you need to do is get a Factory Service Manual from Helm, Inc. Then follow the trees in the service manual to properly diagnose your problem. It will save you time and money.

You need to know what module those codes are coming from too. Just because you get a code and then look up what the primary reason for the code, that doesn't mean that's the problem. All that means is that something is out of the normal operating parameter for that sensor or part. There could be a whole host of things that's causing that code. That's why you need the manual and the diagnostic trees in it. Good luck.