I started having this problem about a month ago and progresively got worst. Now I run so rich at idle that the car wants to stall out. If I run at a steady speed I still run rich, around 10.6 to 1 on my wideband. It even feels like the engine cuts out unless I tap the gas a little more. Sometimes it will jump up to 15 to 1 for a couple of seconds and then start running rich again. I changed the IAC, TPS still no diferrence. Could it be the O2's? I would hate to change those because I have to extend the harness cause of my headers. The SES is on but I dont have a scanner. My local discount auto use to sell them but not anymore.

 

How did you extend the wires to your O2s? If you extended the wires on the sensors themselves, this could be your problem. The wires on the sensors to not respond well to splicing. I would check there first.

 

if u extend the wiring harness side i dont see why it should be a issue if its the O2 sensor side maybe i dont see why either maybe resistance?

 

I see that you have a wet kit on your car, have you checked the fuel solenoid to make sure that its not leaking?

 

The fuel noid isnt leaking because it is no longer connected to the fuel rail. I thought that was the problem too. As far as where you splice the wires on the O2 is concerned. What difference does it make where its at? Whether its before or after the connector makes no difference. Its still a splice, same wires. im gonna go to Northern tools and get a scanner. They seem to have a pretty good one for $170. Auto Xray EZread 2000

 

The sensor wires are stainless steel.... not real easy to get a good solder joint. That's why you extend the harness, not the sensor wires. And, if you ever have to replace the sensor...........

Something is telling the PCM the engine is running lean, when it really isn't. Could be faulty sensors, faulty sensor wiring, exhaust leaks before the sensors, excessive misfires.

Might want to attack the problem ASAP, since the excess fuel will wash the lubrication of the cylinder walls, increasing wear, and the fuel will get into the oil and dilute it.

 

I made the mistake of extending the O2 wires and not the harness when I put my headers in. The car ran so rich it looked like a black fog machine. Get new sensors and buy O2 extension harnesses. I picked up a pair for 20 bucks from a local speed shop. That'll probably fix it.

-Pete-

 

I picked up a scan tool from auto zone. Ran me $150 but gave me alot of info. Turns out that my SES was for a code P0100 which is my MAF. Im gonna try to hit the junk yard tommorow and hope to find one. This is the second time this happens, thats why I didnt suspect the MAF since I bought one new. Maybe it isn't such a good idea to spray nitrous that close to the MAF I dunno. I had no other code. As far as the stainless to copper connection. Im a Detroit diesel tech for marine applications. I twist stainless to copper wires all day. I twist them together and then heat shrink the whole thing, never fails. You would be surprised how long that lasts.

 

In addition to being hard to connect, when you join dissimilar metals like copper and stainless, you create a voltage offset in the junction that affects the signals. The tiny current of the O2s cannot tolerate this sort of thing. The effect will vary with temperature, age (junction oxidation), etc. So, even if you DID manage to get good continuity, the O2reading will be off, sometimes more than others.

As emphasized above, splicing the sensor wires does not work well. So, one last time, it would be a very good idea to replace the sensors with untouched ones.

 

Before you replace the MAF sensor, check the voltage on the pink wire in the harness connector. Should be +12V. The 97's seem to have a frequent problem with a break somewhere in the pink wire.

 

You are right. I found a MAF sensor at the junk yard but made no difference. I did what u said, I should of thought of it but you brought it up so i'll give you credit. Turns out I had no voltage to the MAF but it wasnt a break in the wire. It was a stupid blown fuse! The 20 amp fuse in the engine compartment thats labeled sensors. I replaced the fuse and it runs fine now. All that trouble for a fuse. I was kinda mad.