Ed2016

Been dealing with the PO442 Code on my C5.

I tried tightening the gas cap. Then purchased and installed a new gas cap. No luck...

Looks like I'm going to have to take it to a shop.

Is a possible EVAP leak something a small shop could handle? Or should I take my car to GM for this one (I try to avoid them at all costs)?

What do you guys think?

04 commemorative

NEVERL8C5

Check the vacuum hose on the passnger side of the throttle body they get a hole in the bottom where the bend is

Ed2016

Thanks NeverL8C5... turned out to be a crack on the passenger side exactly where you said.

flynbyu2

Just another reason why this forum ROCKS!

flynbya2

INDEED!

damilleniumboy

That is exactly what mine did, and it was that little vaccum hose by the throtle body.

KenShores

CMC1998

ED....did the check engine light come on first?

Ed2016

Yep.. the check engine light came on one day. I tried tightening the gas cap, and resetting the code. Then when it returned I tried a new gas cap. When the code returned I finally decided there was a leak somewhere and found the cracked bit of hose on the passenger side of the engine.

Thanks again guys. Love this forum.

JCFILM

I know this is a old thread but I thought I would post my comment in case anyone searches for this code in the future.

I've had that happen twice since I purchased my car.

First time - gas cap has to be replaced.

About 3 yrs and 1600 miles later (last week) had it happen a 2nd time - vent solenoid had to be replaced this time. Around $200 (mostly labor) at my local dealer.

ALLEGRO

Somebody post us up a pic of this please.

Mickeyrx70

It's happened a couple of times in my '02 Coupe also. I checked the gas cap, and cleared the codes, & it hasn't returned in awhile, but I'm not confident of the fix. I'll check the vacuum line tomorrow. Thanks!

jdot

Happened to me a few weeks ago in my 04. Check engine light on; installed new gas cap and cleared code and all is well. My cost $68

Vetteman Jack

Very good info - will save this for possible use down the line.

SEC5

Hello, I just recently had the check engine light come on, I figured out how to pull codes, and this is the only one that came up as HC (PO442 HC). Just previously, the night before the light came on, I ran the gas all the way down, not out, just very low, did a refill with 91, and code still there. Never tried resetting it. Was thinking it was something to do with the fuel since I had car checked out before purchase? But now reading this, I guess it could be something else. But the continual mention of fuel cap makes me think, maybe it is something to do with this. I also have changed oil, and replaced air filter since I bought car 2 weeks ago. So a couple questions... Has this code to anyone's knowledge ever been something very serious, I have only 2 weeks left to protect myself with the lemon law, if this repair will turn into a 1000$ fix??? Also, the vacuum line, where exactly is it? Can someone please post a pic of this part and where I can ind the "hole"?? Next, it is showing a code of HC, is it possible this code was up, and seller cleared it just to sell, and now it is coming up with the (HC)?? Any info would be greatly appreciated!!
Thanks,
SEC5

***EDIT*****
Ok, I ran outside, and reset the codes manually, and the light went out....
I guess it is just a wait and see game if it comes back? I did check gas cap, but was under the assumption that the code would reset itself after 3 good ignitions?? Anywho it is off, for the time being, and hopefully it was just the gas cap being too loose??
Thanks again!!
SEC5