If you can run a data log and watch the O2's you should not have to guess if they are working correctly. If they rapidly change from 0xx to 9xx you should be ok.

 

The thread is so long, and so far from the original stated probelm (there is no evidence it's running rich, at least not from the plugs), that it might be better to start over again.

One thing I would do is have someone check the PCM (aka ECM in your replaced parts list) for the correct program. As I noted in an earlier post, the behaviour in power enrichment mode is unusual. There are a few people here who can look at your tune if you can send to to them, or you could send it to one of the mail-order guys, explan your problem, and my comments on behaviour, and let them determine if the tune is correct.

I'd also be suspicious of those Bosch O2 sensors. Too many LT1 owners have reported problems with them.

 

I agree on going with something like Ac Delco or Delphi. Here is a thread with a little info.

https://www.camaroz28.com/forums/lt1...sensor-773015/

I got mine for under $40 each for the oem ones on Ebay, but they are getting harder to find now.

 

Yea, I came to the conclusion that it is not running rich, probably lean if anything after pulling the plugs.

I sent my PCM bin file off to someone yesterday to have them look at the program. We'll see what they say.

 

Can anyone tell me if the second cable here will work on 93 Z28's as well?

thanks

 

That's the correct cable. Question is, what software are you planning to use?

 

Something free - i think it's called Datamaster?

Will this work for my 93 or is there better?

 

There is a version of TTS DataMaster for the 93. Not the same version used on 94/95. Download is free. 20 uses are free, then you have to pay a license fee.

TTS Power Systems

 

So I changed out the drivers side O2 but I can not get the passenger side out. I took it to 2 different shops and they could not get it out either. I busted a universal using my impact and both shops used impacts to no avail.

Would it screw up the readings if I just left that one alone (wires are already cut off) and installed another O2 bung and sensor just below the flange?

I have installed O2's for wideband sensors before but nothing that will actually be giving the PCM live feedback for tuning.

I don't really want to remove the manifold at this time. I'll be doing headers eventually and am not too keen on removing exhaust studs from aluminum heads unless I have to.

 

Was the manifold hot when you tried to remove the O2 sensor?

 

When I was working on it the manifold was cool. The car was at normal operating temp (hot manifolds) when I took it to both shops. It also soaked overnight in PB.

 

I've heard you will need to throw some heat to it such as a propane torch to get them out. I'm not looking forward to changing mine!

 

I soaked mine for two days in PB nut buster and used heat and it took a breaker bar and a sledge hammer to bust them loose. This was off the car, so I can only imagine the pita being on the car.

 

Well, I got the O2 sensors replaced. Didn't help the issue.

Took it into the dealer and they said there is an issue with cylinders 2 and 3. When they unplug the injectors on those 2 cylinders the motor idle doesn't change. They say it is probably a valve train issue and they would need to pull the heads. They say the injectors ohmed out fine so they think they are working properly.

I told them to button it back up and I'll pick it up tomorrow. Really not what I wanted to hear. I was hoping to not have to rebuild it for a year or 2 while I save up for some better heads and forged internals.

Maybe I will find a used running LT1 and just drop it in for now. What is the going rate for a running LT1 these days?

 

You could do a compression test to see how that looks. If its the heads i, would see whats bad and either rebuild or just fix whats wrong. Could be something real easy. Always a little cautious with dealerships, since they usually throw parts or recommend major overhauls.