Been fighting codes for about a 1-1/2 years now. 2002 GP-GT 85,000 miles. Present codes are p0102 and p0420. I know the first is for the maf and the second I believe is for the cat or maybe an o2 sensor. Here's the rub. The Cat was replaced about 11 months ago along with an o2 sensor a few months before that. The maf was replaced about 6 months ago. Presently the idle surges between 700 and 1500 rpm. It doesn't do it all the time. Mostly at initial start-up and then when decelerating off the highway. It seems to fluctuate for 10 seconds or so and then settles in at the proper rpm. Any input would be greatly appreciated.
Thanks
Ed
