1PT-SICK

Just got an 06 Si coupe...a little weird at first but im starting to really like it lol As far as i know its only got a catback exhaust (skunk 2 - trade me your stock for it lol) anyways, thats the only engine mods it has. Im throwing P0420 and P0325...would the skunk 2 have anything to do with the 420 code even though its only a catback??? And anyone have any info or a link that you could give me for the knock sensor code? The car runs and drives fine but kinda idles weird sometimes like if i come to a stop it kinda stays around 1200-1500 then after a few seconds it goes to normal like 900-800rpms anyone help me out?!?!

I did search it, couldnt find much info. seemed like everyone had a bunch of stuff done to there car that threw the same codes.

RICO_

If your car is idling funky i would definitely take it to dealer.....moreso just for that knock sensor issue itself. That's something you don't want to ignore. I don't think the catback exhaust would affect the catalytic converter. Plenty of people have put on the Skunk2 exhaust and I haven't heard anything involving that type of code as a result.

1PT-SICK

Yea, i have a 90 day warranty on it but if it was just something simple that i could replace i would rather do it myself rather then drop it off somewhere and be out of a car for a couple days....oh well, might just do that. Anyone gonna any other opinions?

Greg50Lt

You need now more opinions. RICO gave you the best advice you can get right now.

We dont know the story behind the car such as mileage and if you are the 2nd, 3rd or 4th owner. You have a 90 day warranty on what? The car?

Just take it to the dealer and have them see whats up. Or buy a new knock sensor.

1PT-SICK

Well I looked into it...there was no knock sensor on it at all!!!!! WTF?! lol The clip was just hanging there. So im hoping that i can just put one in and my problems will be solved.

Crossing my fingers that since there is no knock sensor thats what was causing the rough idle and then maybe making it rich causing the P0420 code to come on. Hoping my cat. is still good

EnvyMySi

no knock sensor?? i thought dealers are supposed to authorize their cars b4 selling them?? and didnt u test drive b4 buying???

1PT-SICK

Yea i dont know, i drove it and it ran pretty good- i never drove a car with a K series in it so it was all so new to me. At first i thought something was wrong with it rev hanging lol later i read that its normal.....anyways, I told them i'd buy it if they did new tires, alignment, new fog light cause one was cracked, and then took care of the check engine light. He blew it off like it was no big deal. When i went to pick it up i was in such a hurry and had my girl with our screaming kid out in her car waiting on me. I drove down the road and the light come back on...............im rambling lol Read the next post how i fixed it.

1PT-SICK

Picked up knock sensor from a NAPA for an 06 Si.....wouldnt plug in to the connector? Did some research...then ordered a knock sensor for an 07 Si- FIXED EVERYTHING. Idles great, knock sensor light went off, cat. codes hadn't come back on either problem solved.

Greg50Lt

How much was the knock sensor? Also does anyone here kno what kind of damage this could have caused, if any?

1PT-SICK

Well i work at a NAPA Machine Shop so i get employee prices- dont know the original walk in customer price but the first one i got for the 06 was around $32, the one for the 07 was almost $50. Not sure why the almost 20 dollar difference, almost looked the same lol

RICO_

It can lead to pre-ignition and detonation which (if severe enough) could bend connecting rods and compromise the head gasket. The sensor helps the computer prevent that by adjusting the timing and/or fuel mixture. So yeah it's a pretty important little device.

2008fijibluesi

Take the receipt of that knock sensor back to the dealership that sold you the car and have them pay for it.