GTP with problems

[gojo83]

long story short it is a 99 GTP bone stock except k&n filter. I am unsure on the tune up items we are slowly getting to that. it was bought a month ago and she needs it for mostly a highway car then a little fun on the weekend but the big thing is she has constant KR and it worries me. there is 106k on it, is there anything that could just age related causing the KR . also I am going to dremel out the front manifold and slap it on there and gut the air box. I will do the fuel filter and see if that helps but is there other ideas that I can use as well as advice on a mileage tune. she uses this car as a commuter car over 100 miles a day. any insight would be great

[louvered97gtp]

What sparkplugs and gap? Have you checked wires to see if they're good? Also, bad o2 sensor could possibly contribute
Edit: Looking at scan, your O2's aren't where they need to be at WOT. If I recall correctly from all the reading, I think you need to be at 940 range when you hit 100% throttle on a GTP.
I'm sure others with experience will chime in, but I got rid of my KR by adjusting the timing. you can also try cleaning you MAF sensor and your IAT sensor to see if these help as your readings could be off and affecting your tune.

[johnh]

So first, clear up any mechanical issues: Clean the air filter and intake tract, carefully clean the MAF (learn the right way to do it so you don't wreck it), new spark plugs, new wires (stock replacements are fine), get oil change, coolant system flush. Clean the TB as well.

As mentioned above, replacing the O2 sensor might be helpful too. Your O2s don't have to be 940 ish...really anywhere from 915-960 are in the stock range..(I don't have HPT on this comp so I can't look at the scan).