I dont think one is causing the other but I believe that I have one common problem which is causing both the CEL and Traction off light to come on. I have done the Vac leak check and all is good. my idle is smooth running @ 800 rpms. I cleaned all my positive connectors and negative grounds and all is nice and clean. I have read on this board that a person had this same issue with the two lights but I forgot what he did to clear it up. I read that billboost had replaced his cables to get ride of p0171 but mine looked pretty well with slight corosian at the cable coming from the alt.

I will do a volt test but im not sure how to use the device due to it not being mine. what do I put the postive line on and the negative? What do I turn the **** in the middle to get the correct reading? If the alt is putting out the correct charge then I will replace the positive cables. I have 116k on the car bought from someone else so im not sure on the oxygen sensor but being that he put bosch plugs in it :( im sure he used a bosch oxygen sensor so I will change that asap as well.

Set the **** like this:



Assuming it looks like that. Make sure you have it on the direct current side set to 20(since it'* a 12-14.4volt system).
If you're still not sure, we'll try to be a little more descript.

You can test by starting the car and putting the positive cable on the positive battery terminal, and the negative cable on any bare metal on the body, or the negative terminal. You should see a reading over 12.x volts. You can check the voltage of the battery with the car off, and then test it with it on to see the difference if you want to reassure yourself.

I'm afraid I can't answer the questions regarding the CEL codes....

I removed my MAF screen months and months ago before I had the K&N intake. Pretty much immediately I got a Check engine light (the code I scanned later was P0171), and my TC light came on as well. I couldn't figure out how they could be related, but I'm pretty sure it was. I forget the explanation someone gave me on why. I'll have to search...

What did you end up doing to eliminate the CEL problem? I think that I read some how the TC works by removing timing and applying brake. I think running lean removes timing so it may trigger the TC light. :? Im just shooting in the dark here so dont jump on me for guessing. But it seems as if the light only comes on during idle but when crusing it goes off immediatly. :? . That leaves me to think that there is a charging issue, being that you get your lowest charge @ idle, thats what lead me to think bad battery cables coming from the alt. :? I dont have a K&N BTW.

I got rid of the light by putting the MAF screen back in. That solved both lights. I knew I had a vacuum leak at the EGR tube, and I thought removing the MAF probably pushed me over the edge. It could have been just the horrible rough idle I had.

This is a quote from the thread I had when I removed the MAF and got the lights. IDK of the accuracy of it or if it was my problem. And come to think about it, IIRC, when I pulled the codes after this happened, one of them may have been something with low voltage.

whats IIRC? :? I will know more when I check on the voltage of the alt. I removed my screen a few months ago but I still have the OEM style filter in there. I will work backwords towards replacing the screen after I check on the battery cables and the oxygen sensor.

IIRC = If I Recall Correctly

I still had my OEM airbox when I removed mine too, which was probably the reason the idle suffered. Some don't have issues when removing them though.

Hi Bandit01

I've referred your other post here. Let'* recap. You are getting a P0171 and mention following my lead on clearing it up. Since...I've learned more.

The P0171 code is the O2 sensor reading properly. The pcm is adding fuel to the engine at a rate above the expected amount and therefore is telling you the fueling is out of spec.

The MIL you see is because it take 2 consecutive starts with a lean condition for the light to come on and 3 consecutive starts without the problem for the light to go back off.

You mention a little corrosion on one battery cable. Did you remove the boots by the battery to inspect the cables? If not.. this is your first step.

When you cleaned..did you clean the block where the grounding battery cable attaches to it? If not..this is the next step.

Have you removed and cleaned the ground at the back of the block by the oil pressure sender? This is the main ground for the sensors. If not..this is step 3

Have you checked and cleaned the MAF sensor? This sensor is listed as part of the diagnostic tricks. Unplug the sensor and go for a drive..does the CEL come back on? Is the sensor dirty or bad?

Another possibility is to check the connection at the evap purge valve. This is the black square item with two vacuum lines and one connector behind the alternator. Make sure the vacuum line from the TB does NOT connect to the fitting on the evap purge valve that is labeled "CAN".

So i have had to have three consecutive starts without this lean condition because it did go off at one point and then came back on.

I did all this stuff but like I mentioned the previous owner put electrical black tape around the cable running from the alt to the battery. I will change the positive lead cables and see what happens.

I will do this next because I remember when I removed the alt cable to the battery I put the cable close to the area by the MAF sensor. I didnt see a spark but I have seen weird stuff happen before. Something else I wanted to mention. When I was messing around with the TPS and MAF connectors with the car running I pulled them both out. The connector for the TPS threw a low TPS input code but the MAF didnt throw one. If the MAF was working properly wouldnt it have threw a low input code also when I pulled it?

Will check on the EVAP also.

Having a good day or a bad day.. P0171 is persistant and one or two seconds w/o the light is merely it'* way of antagonizing you.

Honestly.. do all the cables.. after checking that evap.

You shouldn't pull the connectors when the car is running. Don't pull the TPS, only the MAF.