HFC or test pipes are the usual components that cause rasp (especially TPs), so swapping out other parts will likely not make the rasp (if present and caused by HFC or TP) disappear.

I got a SES (CEL) light yesterday, and I took it to the dealer to get it checked out. They said it was cuz I did not have any catalyric converters installed. ;) LOL Totally forgot I had the ERZ HFC's installed and that was probably the reason... They cleared it, hope it doesn't come on again. Been almost a year so can't complain!

Anyone put steel wool between your 02 sensor.

Knock on wood have 150 miles on cats w no CEL. If it is infrequent I will just clear when necessary.

Should work, I have read it helps with the flow against the sensor?

I have been getting the SES light every 50-200 miles the past year. Really getting annoying! I think I need to get the extended O2 bungs. Anyone install them that fixed this SES issue for good?

I used extended bugs on my Stillen ones. Cleared the code and never came back till I switched to test pipes lol. Worth a shot, you can get em off ebay for $15.

I had the same issue on the ERZ HFCs until I installed the ebay extenders.

you dont need extended o2 bungs. waste of money. use steel wool. ive said it many times before all over these forums. in order for steel wool to work you need to put on some work gloves, grab a nice chunk of steel wool, and ROLL it into a tightly wound ball. it needs to be a ball just about the diameter of the o2 sensor bungs. once you get it that diameter (add or subtract steel wool) stuff it in there. you'll find that the o2 sensors wont go in. thats alright, stuff that bitch in there and screw the o2 sensors in tight, but not too tight!

i learned this from trial and error. i had the SES light on after every few hundred miles. i would go down there, stuff some more steel wool. didnt work until i actually rolled it into a tight ball and stuffed it in the o2 bungs. 20k miles later, no SES ever.

Yeah, after about 15k miles on the ERZ's, I started to (still get) the CEL codes. lol, I have just got use to looking at the check engine light being on. I've been lazy about it but will probably look into getting the extended bungs or steel wool.