I have a 1994 3.4 camaro that is really irritating me. If the drivers side o2 sensor is plugged in it runs really rough, if it is unplugged it runs somewhat decent but not good. It always runs rich, cruise control does not work, and heater will not switch off of the defroster vents. no luck with codes either, any suggestions where to go from here, besides the scrap yard?

 

I tried scanning it for codes, but the Actron scanner did not make the check engine light flash, it just stayed on like normal.

 

If I recall right you need an actually scanner for 93-95 4th gens. All what you have there just jumps the terminal (which I can do on a 3rd gen with a .02 cent paper clip or staple). You need an actual handheld OBDI scanner (what you have is not a scanner based on what you've said) that will pull the code from the computer and display it on the scanner. Those are getting harder and harder to find though. you can't even buy an OBDI scanner around here from a store. all they have is OBDII. You're gonna have to go to ebay for that one i'd say. I can tell you with some certainty that you do need to replace your driver's side O2 sensor though based on what you've said. Cruise control is going to require a new module. go to a junkyard and buy one on the cheap. Brand new one is gonna cost an arm and a leg. Did that with my old truck and it worked beautifully. the running rich could be connected to the O2 sensors. replace the O2 sensor first and see if it's still running rich. If you can borrow a real OBDI scanner and pull the codes then do that as well. Hope these suggestions help you

 

you dont need a scanner, take a paper clip, (They do actually make a tool for it, I carry one on my keyring) and jump the two connections on the two terminals on the top right of the diagnostic port under your dash. Your engine fan may come on, no big deal. It will then flash you CEL and theres your codes. It is the top two, should be the only two right next to eachother. It wont spark or shock you or anything like that.

It sounds like that o2 sensor is bad and unplugging it forces the computer into default and it starts guessing.

you will have to look underneath your dash and see if you can find your vent controller and see if a vaccume line came off or broke or something, could be on the back of the HVAC switches too.

For your cruise, check the switch on your brake pedal, I believe its the top one, I have seen a lot of them break or pop out of the holder. if it comes out, then the cruise module thinks the pedal is pressed so it wont come on.

Any other questions feel free to post up. If you cant track your codes down, we can try to help ya out.

Diagram with some instructions just in case your not sure----
http://www.automotivetroubleshooting...e_testing.html

 

I probably should have said that the o2 sensors are both new, as well as the map and maf sensors. the tps only has about 3.8 volts at wide open throttle, could that be the cause?

 

If you have a way, take it off of the car, and go to your local auto parts chain, they should be able to test it. Maybe call them first to confirm they know what theyre doing. Im not sure on the voltage, Im running on my second day of no sleep and Id have to dig my book out to check, it may even be on this site somewhere. I'll see if I can find something for ya and post back.

 

Ok, first of all, thank you all for your help. I figured it out. Someone who owned the car before I got it changed the plug for the map sensor and spliced the wires back together wrong. It was a fluke that I even noticed it because I was changing the spark plugs this afternoon, and my wife noticed the electrical tape when I bumped the wiring harness. I checked the splices to see if they were loose or anything and noticed that two of the wires were crossed. So, I fixed them and we are back in business. No more SES light, and no more rough idle or stalling. Now I just need to fix the heater selector situation, and align the front end. Thanks again.