Hello, I had an engine error code about a week ago on my 98 civic. I took it to the mechanic, he read the code, which said there was a transmission problem: incorrect gear ratio. He checked the transmission fluid, which was alright, and said the code was likely wrong, it would be like driving a car with 3 wheels, that it was probably some computer problem. He switched the check engine light off, and told me to come back if it came on again as that would indicate an actual problem. It came on again yesterday, I went to an auto parts store, had them read the code, this time it was code PO730 transmission fault: faulty shift control system; probable causes: low transmission fluid level, poor electrical connection, failed transmission shift control system. A couple of days before I got the initial check engine warning my radiator had failed and engine had overheated (with steam coming out of the hood before I noticed). So this might have something to do with the check engine light coming on suddenly, or it might be coincidence. Anyone know what could be the matter, since the mechanic didn't find anything wrong initially? Is there anyway to avoid a potentially expensive repair here? The car seems to run fine, so what if I just ignore the check engine light? Or can anyone suggest a cheaper alternative repair to what the mechanic is likely to suggest? Thanks.