Have you checked to make sure your brakes aren't dragging or that your front axle isn't partially engaged?

 

I replaced my rear brake calipers awhile back. Nothing is dragging now.

I haven't checked if the front axle is partially engaged.. How might I do that..?

 

Really! Go from a .60 gap to a .35? This can't be for real....unless you are running points!

 

Jack up the front end and spin the drivers side tire. The other side shouldn't spin.

 

What exactly should the gap on the plugs be? I believe I'm running .43 or .45.
.35 doesn't seem unheard of, my turbocharged Honda ran .25- but .60 seems waaaaay too big!?

I'll check the 4x4 action.

 

Pitch the NGK's and put AC Delco 41-993 plugs in it with a gap of .060"
While you're at it, use AC Delco cap & rotor too. (yes, it does make a difference) Have you checked camshaft retard? Spec is zero degrees, plus or minus 2 degrees at 2,000 rpm. It has a direct affect on ignition timing and makes a huge difference in gas mileage if it's off too far. It will not turn the SES light on until it's off ~27 degrees or more.

The spacer on the downstream oxygen sensor will not keep the light off. When the PCM runs the monitor for the converter, it switches fuel mixture full rich then full lean. Then the PCM watches how long it takes for the sensor to report the change in fuel mixture. If it takes too long, the light comes on. If it reports too rapidly, the converter isn't working, (or gutted) and the light comes on. If the converter is working properly, sensor voltage should remain steady, (around .4 volts) at a steady cruising speed. The monitor does not run continuously, a certain set of parameters must be performed before the monitor will run and complete the test. If they are not duplicated precisely, the monitor will not complete the test. Performing step 7 of the General Motors Driving Cycle will force the monitor to run and complete the test.

 

I doubt my brand of plugs will effect it. I can regap if neccessary. However I do not feel the need to replace them, they're brand new and do their job. I run NGK's in everything and never have issues.

I can tell you for a fact that it does indeed keep the light off as far as daily driving goes. I had a steady light for months and I put the spacer on and it has been off since. Whether or not it gives the PCM the correct information is a different story, but it isn't throwing a code for anything. Does performing the test do anything for me other than turning the light on, if the spacer doesn't stop it?

The 4x4 is not engaged. Just to clear that up.

I will look into the cam retard, but I won't be able to check and/or reset the cam retard for at least a few more days.


Thanks again for the help everyone! I appreciate it.

 

You asked for advice to help your fuel mileage. It's up to you to decide if you want to take it or not. I don't care one way or the other.

The monitor obviously has not run and completed the test.


Step 7 must be followed exactly as explained before the monitor will run and complete the test. If it is not followed exactly, the monitor will abort and will not run again until it is followed correctly, then it will complete the test. During daily driving, it's entirely possible for the monitor not to run and complete for months, or more. If you live in a State that requires emission testing, it will fail immediately if the monitor is incomplete.

 

I understand this. But does it do me any good if the code is showing or not?

 

The downstream O2 sensor has absolutely no affect on engine performance. Its sole purpose is to monitor the efficiency of the catalytic converter. The only way it would pose a problem is if you need to pass an emission test. Some states require it before license plates are issued.