Po442 Error Code

Hey Guys,
It's been 24,000 trouble free miles since I last did any wrenching on the car. (Aside from oil changes and tire rotations). I just woke up to a PO442 error code today. A trip to autozone for a scan tells me I have a vaccum leak somewhere in the system. Is there a typical location where these cars are known for vacuum leaks?

Autozone print out says:
- defective or loose gas cap
- evap canister or hose cracked
- purge or vent solenoid defective
- vacuum leak at engine

Gas cap has some checking on the rubber seal. Haven't looked at anything else yet.

VegasScott

Specifically, 0442 is the 'small' evap system leak.
While any vacuum/vapor leak between the tank & the engine could cause it, I'd make sure the cap was on good & tight and just drive it for a week. It takes 3 successful drive cycles to turn the MIL back off, but the test can only run when fuel level and air & coolant temperatures are within certain limits...

Eldo wrote:

Specifically, 0442 is the 'small' evap system leak.
While any vacuum/vapor leak between the tank & the engine could cause it, I'd make sure the cap was on good & tight and just drive it for a week. It takes 3 successful drive cycles to turn the MIL back off, but the test can only run when fuel level and air & coolant temperatures are within certain limits...

WOW! Thank you! That is excellent information. What is a "drive cycle" defined by? Ignition events?

I recently serviced the little plastic elbow from the plenum because it was leaking. (actually Pep Boys did it because I was in a rush and didn't have time - first time anyone other than myself touched the car)

I have another issue which shouldn't be related, but I have heat on the passenger side of the car, but not on the driver's side. This issue apeared about a week before the P0442. Any ideas?

Thanks!
VegasScott

Light went out this morning.

VegasScott

VegasScott wrote:

Light went out this morning.

VegasScott

Cool!

Eldo wrote:

VegasScott wrote:

Light went out this morning.

VegasScott

Cool!

Consider replacing your cap; you can get a new one pretty cheap from gmpartsdirect.com or monsterpartsonline.com - and maybe even from your local GM dealer if he/she sells enough of them. Parts stores have caps that will fit but you'll have to live without the tehter or transfer it from the cap you have to a new one. New caps come with a better attachment of the tether to the cap (the old style tends to break at the cap).

Personally, I don't like tethers... Doesn't the fuel door still have a hanger for the cap on the '98s?

My '98 has a notch cut out of the part that latches the gas door so that you can hang the tether and the cap.

My gas cap came apart a couple of fill-ups ago - I just pushed it back together, and so far so good (no SES light). Am I living on borrowed time (time for a new gas cap) or just concerned for nothing? How much is a replacement cap online?

STANT Part # 10817 $3.72 on rockauto. no excuse for not getting it replaced ASAP. The acdelco cap is $8 (normally better quality).
You will have evaporated more than $3.72 in gas by the time the part has arrived...

Thanks - of course I was at NAPA earlier today - I'll be by there later this week, and will add this to my list.

otto95 wrote:

My '98 has a notch cut out of the part that latches the gas door so that you can hang the tether and the cap.

So there's no "cradle" on the back side of the door/hinge itself to hold the cap after '97?

That's interesting. So it sounds like the 98+ have a little nub to hang the tether on whereas the older models have the slot that holds the threads of the cap.

My 97' has the latter.

DEMonte1997 wrote:

That's interesting. So it sounds like the 98+ have a little nub to hang the tether on whereas the older models have the slot that holds the threads of the cap.

My 97' has the latter.

That's what I've got.
But I figured anything's possible, since my buddy's '99 Suburban has both a tether AND the slot/cradle on the back of the door... despite having the annoying 'new' cap.

What worked for me (admittedly a while back) was a Dorman gas cap tether kit, their part #55300. Should be less than $6.00, and fits the OE cap when the original tether breaks.

If you look carefully at the *replacement* cap, if you get a Stant, you're likely to find the recessed place the tether ring (on the old cap) rides in. You can transfer the old ring off the old cap to the new cap but it's difficult because the ring fits real snug. The Dorman retrofit tether uses a spring steel ring that goes on relatively easily. It's adequate.

I had replaced tether once, replaced that gas cap with a Stant and moved teh tether, when the Stant failed I bought an OE cap from the dealer - surprise surprise **different** design for the tether. Later the gas filler pipe filler (if you search you'll find comments about my kludge to replace the filler with a Park Avenue filler) and got a different cap (for a 2004 PA) because the old cap would not fit the new pipe.

Albertj

So should replacing the gas cap be a preventative maintenance item or is it fine up until the point it breaks?

Eldo wrote:

DEMonte1997 wrote:

That's interesting. So it sounds like the 98+ have a little nub to hang the tether on whereas the older models have the slot that holds the threads of the cap.

My 97' has the latter.

That's what I've got.
But I figured anything's possible, since my buddy's '99 Suburban has both a tether AND the slot/cradle on the back of the door... despite having the annoying 'new' cap.

My '99 Chevy Astro has the same thing (both a tether AND the slot/cradle on the back of the gas door), but it's a much bigger gas door than the Riviera.

My '98 has a 6/97 build date (which I thought was very early for a '98) according to the driver's door sticker, but it looks like I got the '98 gas door, not the '97 style.

here's what my 1998 Riv looks like...



VegasScott