Error Code PO 442

[slv01sc2]

I have a 2001 SC2 with 83,600 miles on it. On the way to work today my service engine soon light came on. I checked the gas cap to make sure that it was on tightly. After work the light was still on so I went to Autozone and the machine read PO442 a small leak exists in the emission evaporative system. I called my retailer and they think I may need a new gas cap or have a possible fuel line leak. I don't know if it is my imagination but the car sounds louder from the front, I wonder if I have a possible exhaust leak off of the engine. At 60,000 miles I had a probelm with the car idle, when i would come to a stop the car would idle at about 400 and almost die and kick back up again. The car is doing something similar but not all the time, it is only dipping to about 600rpms. Would it be worth my while to go get an new gas cap and see if that solves the problem or does anyone know if it is something more.

[PeteB]

From www.obd-codes.com:

Causes

A code P0442 most likely means one or more of the following has happened:

• A loose or improperly affixed gas cap
• A non-conforming gas cap (i.e. not factory/original brand)
• A small leak/hole in a fuel vapor hose/tube
• Other small leak in EVAP system
• Faulty vent o-ring seal

Possible Solutions

With a P0442, the most common repair is to:

• Remove and reinstall the gas cap, clear the codes, and drive for a day and see if the codes come back.
• Otherwise, replace the gas cap, or
• Inspect the EVAP system for cuts/holes in tubes/hoses

At 83k, you are probably ripe for some exhaust work. The first thing to go on my car was the flex section in the front pipe assembly. I wound up replacing everything back to the muffler.

WRT the low/fluctuating idle, how are your spark plugs and wires?

[slv01sc2]

Pete,

Thanks so much! You shure know your stuff. My plugs were lastr changed at 60,000 miles and the wires are original. I was planning on changing both plugs and wires at 90,000 miles. I'm going to go and get a new gas cap today and hope that it fixes the problem.

[wrg813]

Don't ask me how I know, but I suspect we will start seeing P0442 codes on 00-01 vehicles start popping up. Code P0440 is usually a loose or missing fuel cap. Recommend getting the code cleared and it may never return again. I have seen cases where it reoccurs intermittantly with no symptoms and no concerns detected. The factory has recommended everything from fual cap, ect(and connector) and ecm replacement based on their cases on file. The latest information I have recommends thermostat replacement(I dont know why). That may have changed in the last few months though. Good luck.

[slv01sc2]

I went to my retailer last night and bought a new gas cap. The gas cap looks completly different than the one that was on the car originally. I went and got gas right after and then drove 30 miles. The light is till on. My temperature gauge seems to be acting normal. Thanks for any suggestions. I guess I'll have to make an appointment and pay $60 for Saturn to see what's going on.

[PeteB]

Did you reset your PCM?

[slv01sc2]

I didn't reset my PCM(what is that?) and how do I reset it? Thanks so much for all of your help. The dealership made me beleive that if the gas cap was the probelm the light would go off right away.

[SaturnTech]

You can't reset your PCM...in an older (1995 and older) car it could be done by removing the negative battery cable for a few minutes. It's no longer possible on a 1996 and newer (OBD II) car. It is federally mandated that the information in the PCM(including trouble codes) be stored even if the battery is disconnected. The only way to properly clear the code from the PCM would be with a scan tool.

[SaturnTech]

PCM=Powertrain Control Module....the main computer for your car, it's where trouble codes are stored among other things.

[Scout238]

I have a 97 and a 96 SL1 and disconnecting the battery clears the code..... Though my method is now a scan tool since I got one.

[PeteB]

Originally Posted by slv01sc2

I didn't reset my PCM(what is that?) and how do I reset it?

Oops, sorry I didn't explain earlier, but wasn't sure of the procedure for an '01.

[PCF]

I have seen the same issue on my 2000 SL2 with 160,000 miles. I replaced the fuel cap, but the code came back.

A few weeks ago, I changed the thermostat. I have not seen the code since.

An earlier post on this topic related the thermostat opening position with confusion on the PCM and temperature readings. The poster had experience that thermostat replacements fixed the code in every case.

It can be reset with an OBD-II reader (if you or your friend has one) or Autozone will do it for free.

[slv01sc2]

Thanks so much for all the replies. I have an appointment on Saturday morning with Saturn. What do you all suggest I tell them to look for,or will they automatically suspect the thermostat? I worry sometimes that some people are not as up on things as peoiple on this site. The code is still just the PO442. I hope Saturn has the thermostat info. The car also sounds a little bit loud when accelerating. When idling the car also sounds loud from just the front end as well.

[PeteB]

Seeing as the cap has been eliminated, you must have a leak in a fuel vapor hose or connection. This should not be expensive. You could inpect your EVAP system yourself, which might turn up the problem.

[slv01sc2]

Pete,

Thanks so much for all your advice. How you one go about inspecting their evap system themselves?

[PeteB]

You're very welcome, and I hope you find the trouble. If not, a shop fix shouldn't be terribly expensive.

There's a diagram here; note that one line goes back to a fitting at the fuel tank, so is part of the system:

http://www.autozone.com/servlet/UiBr...3d80199f92.jsp

[willfxp]

If the gas cap was the problem, it should "clear" itself after the computer checks and rechecks that the problem went away. It might take a few engine starts, or running time.

[slv01sc2]

I took the car in to Saturn today and it is now fixed. The problem was a chaffed wire that was connected to the evap, system. I now have a new gas cap that I paid $28 that I do not need. The new gas cap looks completly different from my old one. I did buy the new one at Saturn. The new cap does not have holes on the botton that have some type of metal inside. Anyway, thanks to everyone who gave me advice. Saturn did not charge me to fix the wire but I had to pay $60 for the diagonstics. So my SES light problem cost me $90.

[JohnASmith]

I got an error code 442 on my 2000 SL2. I tried res-installing the gas cap but the "check engine" stayed on. I removed the battery cable and the light is now off. Isn't the 2000 model supposed to reset itself? Is the "check Engine" light likely to come back on? Thanks.

[wrg813]

Make sure they documented the exact code(p0442) so if it resets, you will not be responsible for repeat diagnostics. I hope it is fixed, but as I said earlier, you may be chasing an intermittant concern that has not yet duplicated since the code was cleared during service.