So I have a SES light all the time normaly, for the !Air system. Well I read the codes randomly to see if any new ones come up so I can fix the problems. Well a few days ago the SES light went out. It was out for a while, then it came back on in like 5 starts, then it went out after a few starts, then a few starts later it was back on again. So today I read the codes, and holy ****, here they are

p1642
po500
po410
po300
po174
po171
po131
po134

Now the random missfire is explainable, I got some coolant on my opti friday and it ran like crap till it all drained, now its running just as before the radiator hose cracked.

I just replaced the passangerside pre cat o2 ( no cats, but haven't been able to located any sims, where would they be? ) and the car is running really rich, really, really rich, I think the computer is seeing that its running lean and fattining it up... So do I need a driverside pre cat o2 as well?

 

Copied from Shoebox's LT1-specific code list.... bookmark it and look them up when you get them:

http://shbox.com/1/Dtcs.htm

P1642 = Fan Control (FC) relay 2 and 3 control circuit
P0500 = Vehicle Speed Sensor (VSS) circuit (manual transmission only)
P0410 = Secondary Air Injection (AIR) system
P0300 = Engine misfire detected
P0174 = Fuel trim system lean Bank 2
P0171 = Fuel trim system lean Bank 1
P0131 = Heated Oxygen Sensor (HO2S) circuit low voltage Bank 1 Sensor 1
P0134 = Heated Oxygen Sensor (HO2S) insufficient signal activity Bank 1 Sensor 1

The last 4 are obviously related. I wouldn't jump to the conclusion that its directly caused by the O2 sensors, but it is possible they are both contaminated and stuck at low voltage, forcing the PCM to add extra fuel the engine doesn't need.

The AIR system is obvious.

Do the others correlate with any problems you have had recently - fans not working, speedo not working?

 

yeah...he had the miss fire problem...but once the coolant evap'd it was fine.

 

how long ago did you put on your headers? the reason i ask is because new headers destroy o2s. i found that out the hard way. i put brand new o2s in my new headers and they quit working after 500 miles. i replaced them a few hundred miles later and now they work fine.

 

I have a manual fan switch, but its not currently wired up ( although the lead off the PCM harness with a resistor in line is still hooked up, so I assume thats that ) and the speedo works fine.

The headers have been on for ~40 thousand miles, I just replaced the passangerside o2 sensor about a week ago.

Thanks for the link, SHbox is a godsend, it really is. Thanks in advance for the help guys!