Check engine light reset?

I'm new to this forum and I hope I'm not repeating a question from brefore. I did a search but came up short. I have a 1990 Toyota Pickup with 22RE and 186,000 miles. I recently had the timing chain and cover replaced. I replaced my gas cap, and air cleaner. When I drive any kind of distance (30miles or more) my check engine light comes on. I had it reset and was fine for awhile and then I made a drive up to the mountains and it came on 20minutes into the trip. On the drive back, it went out on it's own. What I would like to know is if anyone knows how to reset the "check engine" light should it come back on, with out taking it to a shop. Thank for the help!!

You might want to take the EGR valve off and see if it is caked with carbon. That can cause it to go on and off while driving Make sure the ports going into the intake are cleaned out as well. Carb cleaner works well. I had to take a screwdriver to mine to pick out the carbon first. Do not spray cleaner on the diaphram though.

Thanks for the fast response. Not to sound like a complete dumba$$, but will fuel injector cleaner in the fuel tank help with this?

It might but with high miles on a car some oil burning is going to cause carbon build up anyway. Try that and see if it helps. Just make sure to check all ports as I was a complete dumba$$ and had to remove it 3 times before I was able to see/remove all of the carbon. It has been 15K miles and no problem since.

By the way, mine idiot light would also come on at 30 miles. Strange! have you replaced the PCV valve?

I have not done any other service (other than oil changes and the above mentioned timing chain) to the truck sine I've owned it. Is 3rd party parts OK to use, or should it be Toyota only? So I take it there is no way to override the check engine light? (Coming up on emission time and don't want to fail because of a stupid light)