Toyota Repair: Transmission Problems, toyota rav 4, 2003 toyota rav 4

Question
I own a 2003 Toyota Rav 4, 4 cylinder, Sorry, I don't know what kind of transmission I have. I recently am experiencing problems with my engine light. My engine warning light goes on and then it will go off. This happened to me twice now. The time the engine light goes on to the time it goes off is about a day, or day one-half. I think I have transmission proplems, but not sure. I can't afford to spend a lot of money on my car; and I was wondering if there is anything I can do to fix the problem before I have to open my wallet and go to a mechanic?

Answer
Since the light goes on and then back off again it means that the computer sees a problem once and then when it looks the second time the problem is not there and turns the light off, it works on what's called a two trip detection logic meaning it does not see the problem twice in two trips. There is usually a diagnostic trouble code in the computer in the pending code section which could be retrieved. There are two likely causes for this, the gas cap is not sealing or there is an oxygen sensor or catalityc converter problem, try replacing the gas cap, make sure to get the correct one, preferably from the toyota dealer at about $22.00 then clear all codes by removing the negative battery terminal for about ten seconds and see if the light comes back on. If it does contact one of the lrge autoparts stores like Kragen, autozone, advance auto, they usually get the trouble codes for you at no charge, then post another question for me letting me know what the codes are.