Just installed K&N intake.............
Had the dealer order me a new oil cap. It came in yellow. Just going to paint it.
I also had the K&N filter, but didn't want to replace the MAF, so I removed the K&N filter. The CEL cleared. I had the CEL a few different times, and after I removed the K&N filter, and cleaned the MAF, it has stayed off. Cleaning the MAF may have been enough, but I don't want to chance it by putting the K&N back on.
I had the problem with mine for the first 1000 miles, (of course didn't find this thread until after), cleaned the filter without oiling and cleaned the MAF and the CEL has been gone.

About the most you can expect to do with "reasonably priced" HP upgrades are:
Exhaust (my fav is the afterhoursautomotive.com pipes)
software flash
intake (KN, EVOMS)
all three of the above will give you the most improvement, you can continue on with headers, 200 cell cats and RSS intake plenum but that's about it
also depends on how loud you want your pcar to be-
The "sprint booster" module makes for a very perky egas pedal, that is a fun mod.
what year is your pcar?
K&n
just installed mine this morning. Took about an hour to swap them out. Fairly straightforwd really. the only issue I had was lining up the air intake tube with the baffle on the lid. With all the bracing in place to hold sheild steady just the two small bolts doesn't ensure that it meets correctly. With a bit of fidgiting it finally fit. Went out for a ride and can definately 'hear' the difference, sounds nice, and I think I can feel the extra punch above 4,000 RPM. Worth it to me



