SES light on and audio problem

I own a 1997 GMC jimmy with 105,000 on it and its been quite good to sme so far except for a few lingering problems which are quite agravating, first, the check engine light is on, computer scan says that there is an evaporative emission control leak somewhere, i replaced the gas cap for the 2nd time to no avail, i would like to know if anyone has any insight on this. The second problem is with the audio system, it likes to work on only the right side speakers when it is damp out or too cold out. I was told that this may have something to do with the factory amplifier being damaged or something along thoes lines, so i need to find and replace the amp, however i have no idea where it is. Any help here would be great, cause this is sooo horribly annoying, the last problem is the gas gauge is highly inaccurate, reading well beyond full when i top it off, i know someone knows about this problem out there its a commom GM thing from what i am told.

For the evap system, more than likely you have water in it... Disconnect it drain it and let it sit a couple of days (it's under the rear bumper on the driver's side).

As to the radio, it's pretty much shot. You have some trace cracks on the amp board. What happenes is the the traces are seperated enough that they only connected as the unit heats up. Just get yourself a decent unit at best buy or someplace like that. (don't forget to change the speakers, the oem ones suck with aftermarket head units)

Thank you for the advice, i will drain the evap canister as soon as i have some time, i think that they have been mixing some water in at the indian reservation gas pumps.

As for the radio, i guess ill break down and buy a new one, i already have the speakers for the doors so thats not an issue, but thank you again for the advice, you probly saved me a ton of money.

Do you know if thats a common problem with the stereo, i have a friend with a silverado and he has reported a similar problem to me, as did my friend with a 99 Bravada? id love to be able to forward this advice to them and assist them with their problems too, thanks alot

Hey i was checking out your website and liked alot of the modifications that youve made to your truck, especially the gas mileage computer in the overhead console, i have an overhead console now but its only got the temp and compas, how hard was it to connect the new computer up? Also how difficult was the front end swap from the old style to the new style, ive often thought about these things but never heard anyone whos done them before, any help would be greatly appreciated, thanks again