My check engine light recently came on. The error code is P1491. What is wrong and how can I fix it? It has 33K miles now. Also, my truck has always gotten 14 mpg town and 20 highway. Is this about average? Thank you.

Make sure your gas cap is tightened down good, just a sugestion.

Thank you for your suggestion. I have had three fill ups since the light came on and tightening the gas cap did not make it go out. It still runs good with no obvious problems other than the light.

autozone or other auto parts stores will read the codes and tell you exactly whats going on for free

I think I had the same problem....

I checked it out at Autozone and the dealer...my problem was the condenser fan drew too much current and blew the fuse. Check your fuse for the AC condenser fan. The dealer wanted crazy money to replace the condenser fan...there is a TSB on it I believe. I replaced my fuse 10k miles ago and I haven't had an issue since. Even the error code reset and cleared out go figure.

You can also try resetting you computer by disconnecting the negative battery lead for a few minutes. Some of the codes won't clear until so many starts without the problem present.

Thanks everyone. I will certainly try your suggestions. This is a very good forum with good people. Glad I found it.

obdii.com type the code in with the P and everything.