maichor Posted April 15, 2009 Author Share Posted April 15, 2009 I had my harness reworked by Speartech years ago. With the new injectors in, it is throwing PO141 (O2 Heater Circuit Malfunction Bank 1 Sensor 2) and PO161 (O2 Heater Circuit Malfunction Bank2 Sensor 2) codes as well as a random misfire (PO300). Now, I was told that with the PCM tune you Speartech did, that I do not have to run O2 simulators. Why am I getting codes for the rear O2 sensors? Do I need O2, sims? The battery died completely once. Would that mess up the tune? Please help. Thanks. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted April 15, 2009 Share Posted April 15, 2009 Well I really really doubt your rear o2's are causing any sort of misfire/rough running concern. They really have nothing to do with drivabilty at all. Ignore those codes. If it was me I would clean the Mass Air Flow sensor with some brake clean and let it dry. Then reinstall it and fire it up. Lean codes are usually caused by MAF sensor problems. It does sound like you have a fuel system issue though so I wouldn't rule that out either. Atleast cleaing your MAF sensor is darn near free! Did you already buy new injectors? You can send out your old ones and have them cleaned. Not sure where but a simple google search should net you some results! Guy Quote Link to comment Share on other sites More sharing options...
maichor Posted April 15, 2009 Author Share Posted April 15, 2009 I will try the MAF clean, although since I changed injectors I haven't had that lean code anymore. And yeah, forgot to mention that. I put some used but cleaned injectors in and it runs almost the same. I did get a PO302 code once again. But it throws the 300 random/multiple code without fail. Is it possible that I have a bad spark plug or coil? Coil would throw it's own code, I would think. Quote Link to comment Share on other sites More sharing options...
maichor Posted April 20, 2009 Author Share Posted April 20, 2009 Well, after the injectors did not really solve the problem, I started looking at other things. The car ran great before sitting, so I assumed it was fuel related. But, I figured I didn't change the plugs when I originally did the swap and so I bought new plugs and figured I'd try to get a read on what was happening off the old plugs. Here is what I found. Plug #6 fouled, Plug #5 cracked, and Plug #7 mismatch. I drove the car and the monster lives again. I still get at #302 code coming off WOT of even 1/2 throttle at times. The plug looked ok. Any ideas on that? also, anything about the other plugs that is not good? Finally, I am posting the picture of the rust that came out of the fuel rail. All those dots are rust flakes in the fuel in a bucket I used to catch the fuel. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted April 22, 2009 Share Posted April 22, 2009 Have you moved the #2 coil to a different cylinder? I would assume since you have new injectors and still a P0302 code that its not an injector but you never know. I would swap the coil and see if the misfire moves. If it doesn't I would check compression on all 8 cylinders...they should be within 10% of each other, idealy closer than that though(more like 5% on a good solid motor). Quote Link to comment Share on other sites More sharing options...
maichor Posted April 22, 2009 Author Share Posted April 22, 2009 I will swap out the coil. I hope to do it by the weekend. If it doesn't solve the problem, I guess I'm buying a compression tester. They aren't that much. The motor only has 10,500 miles on it. I would hope it is all good. No $ for a rebuild. It really is running much better with the plugs and I have not been getting the other codes anymore, just #302. Thanks for the advice. Quote Link to comment Share on other sites More sharing options...
maichor Posted May 19, 2009 Author Share Posted May 19, 2009 I moved the coil and in the process noticed that the connector was broken. when I tried to move the coil it failed completely and I got a code for coil#4, (WHERE I MOVED #2 COIL) as a primary coil fault. So, I replaced that coil and finally no codes at all. So, thanks to all or your help, it turns out that I had a plug issue on one cylinder, a coil on another, and some fuel issues. The weird thing is that none of these codes popped up before I parked it about 6 months ago. Go figure. The fuel one I understand, but not the others. I'm banging on all 8 now. What a difference! I have a slight header leak at cylinder 2 and when I get off the gas I get a few loud pops as the RPM's drop. I am guessing that the leak may be causing it to be a little rich. Is that correct thinking? Anyway, I will try to get that gasket replaced soon. I am hoping to move on to bodywork now unless more gremlins pop up. Quote Link to comment Share on other sites More sharing options...
Bigdeezs Posted May 20, 2009 Share Posted May 20, 2009 I have a slight header leak at cylinder 2 and when I get off the gas I get a few loud pops as the RPM's drop. I am guessing that the leak may be causing it to be a little rich. Is that correct thinking? Yup...O2s read false air so mixture goes rich...now extra air and fuel in hot exhaust burns...POP POP. Quote Link to comment Share on other sites More sharing options...
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