davidyal

MY 2003 RX300 threw the CE, VSC & TRAC OFF lights a few weeks ago. the code was read as EVAP P0442, and Autozone recommended a new gas cap.

1. Has anyone sucessfully cleared the code using a new gas cap? My old one looks like it is good shape, so I'm skeptical.

2. Is the $7.99 gas cap that Autozone sells (which fits my car) good enought? or do I need the OEM part.

David in DFW

code58

This is only a suggestion but I think anyone who drives a car in this day and age should own a code reader. You can buy them so cheap anymore and the net has good sites for decifering the codes. I ALWAYS cancel a code when it comes up and see IF it comes up again and WHAT comes up first. (is it the same thing?) Remove your cap, clean the lip of the rubber seal and replace. It may never come up again. Codes are definitely help, but are not lasers pointing a red dot on the problem. Still takes common sense and research on the part of the mechanic (or) owner to determine what the problem ACTUALLY is and that the CEL that you got is because of a valid problem or a CEL BF.

carguy07

X2, clear the code and see if it comes back. If you decide to replace the gas cap I would only buy OE.

I think that is one of the codes that you can get if the vacuum line comes off the air box too. May want to take a good look at that also.

sktn77a

iTrader: (2)

I had a CEL with the "evaporative system malfunction" code (don't remember the number). Got a good gas cap from Autozone and cleared the code with a code reader. The CEL light never came back on. The code and light should clear on its own but I was impatient!

salimshah

To clarify, the error code has to be related to evap system. So if the CEL and track are on:

1. read the code.
2. Clear the code.
3. Wait for CEL to comeback.
4. If it does come back, check the code again.
5. If the code points to Evap system then go buy a replacement cap.

Moral: Not all CEL are related to Gas Cap.

Salim

NINmh

I think we're missing the obvious question, is there a vacuum noise when you take off the gas cap? If there isn't, then I would replace the cap, go from there..

davidyal

Thanks for all the tips. I'll test for a vacuum noise right when I get back to the car later today.


THis thread also convinced me to by my own scanner, but I have no idea which model is "good enough" for me. Amazon has plenty, many under $50. Can anyone suggest one from this list?

http://www.amazon.com/s/ref=nb_sb_ss...x=odb2+scanner

NCResident

I also found an autozone gas cap cleared the problem. The autozone cap seemed to provide a better seal. It cleared when I got gas about 3 days after changing the cap. I'm not sure, but I wonder if the code resets on the vapor issue when you get gas as vapor always escapes when you fill up.
Eric Bach

salimshah

The system is pretty elaborate ... one should not run the engine without the gas cap ... lot of purging, venting happens between gas tank and charcoal filter.

Salim

NCResident

I always ran my car with the gas cap. The gas cap sold at the Lexus dealer seems to either provide a bad seal or not age well. I had purchased one of those in the last three years. The autozone one seemed to be a little better designed to get tight seal.