Based on what I read, I don't think the glowing manifold is necessarily a concern. I just put some NGK TR55 in mine which are cooler plugs, and will see how they look in a week. I do mostly heavy stop and go driving, with a one mile long hill everyday on my way to work, so maybe my gas mileage will always suck. That'* the price of driving luxury and living on a hill.

I also ran a scan on my car with an experimental homemade interface and free software, and it came out clean on all malfunction flags. It did indicate some knock retard when I did some heavy acceleration and going up the hill. This is before the new plugs. Premium gas around here is 91 octane. I'll have to try the scan again in a week or so after the ECM has a chance to learn the new conditions, to see if it affects it.

Since I replaced my O2 sensor and cleaned the TB, it does idle smoother, and lower than before, around 750 RPM. Oh yea, I also took out the MAF and cleaned it very carefully with a Q-tip and denatured alcohol. That seemed to smooth the idle a little as well. I got that idea from reading a Ford truck thread. It didn't seem to hurt anything.

If I wanted to stick with AC plugs, which ones would you recommend, standard, platnum, rapid-fire or would it be better to get the NGK TR55'*.

Thanks

ctj

The original AC-Delco are 41-601. As I said in my last post, I'm trying the NGK TR55 plugs to see if there is an improvement. Everything I have checked so far leads me to a hot running condition, rather than lean burning. My theory on that is, 90% of my driving for the last 5 years is stop and go and low engine revs, which probably is building up carbon in the heads, which will increase the compression ratio, which translates to more heat, so running a cooler plug should help. Maybe a top end cleaner would help also, but that'* something I would rather not do, at the risk of causing other problems, (clogging catalytic converter, etc). Also, I tried platinums earlier, which I heard are not recommended for supercharged engines. I'll let you know the results of the TR55'* in a couple weeks, after I give them so time.

The funny thing is, the plugs I removed a year ago (AC-Delco 41-601) had the normal tan appearance you would expect, but they had 50,000 miles on them, and that was the first time they were ever removed. At that time, I had a bad plug wire, which I also replaced as a set. The car had 10,000 miles on it when I bought it.