My 1998 Honda Accord with 126k miles started having transmission problems, which started with rough shifting to finally I could not drive it as my second gear seemd to be shot (could not shift past 1st gear). Anyway, coming to grips with the inevitable fact that these honda transmissions were defective, I took my car into the Cherry Hiil NJ AAMCO dealer who quated me about $2,600 to rebuild the trani. I told him I did not have that kind of miney and needed him to give me some alternatives. He then called me back with a $1,800 quote, which I was able to reduce to 1,650. (Frankly, I ave a feeling there was not mich wrong with it, but anyway). So after getting the car back, I saw that the Check Engine light was still on, but the car drove fine. After a few days, all of a sudden it would not start, and then 5 min later it started up. The same thing happend a couple of days later, and then the third time (this time at home), it just would not start up anymore. The starter would click once, but that's it. (I checked the battery, and it was fine). I called the AAMCO guys who were already pretending to not remember me and then told me to have the car towed to the shop and they would look at it. Yup, $$$ i got the picture... a good chance that I was being baited. Coincidentally I saw an AD on TV that same day about a device called CarMD, which could read your Check Engine Codes and tell you wat is likel the probelsm plus cost of repair... so that you can be ready for your mechanic and not get scammed. I made the $120 investment and got it. I ran the diagnostic with it, and it gave me two codes P0240 (Cat Coverter... or potentialy O2 sensor problem) and P1739 (Auto Tramsmission clutch 3rd pressure switch problem). I started investigating all these scenario on the net and frankly did not find anything meaningful other than tellig me wehat these codes are. There were suggestions that these could also be triggered by simple problems such as Gas Cap, Fuse, Trani Fluid, etc. Nothing worked. The only other thing i read was that sometimes codes can be left behind from a previous issue that was corrected, but the code was not cleared. This led me to thinking about trying to clear the codes and see what happens. Finally in one thread in this forum, I ran acorss a note that said how to clear the codes:

Pull out Fuse #13 (labeled "Clock /Back Up") and wait for 10 sec, then put it back in.

I did it, and it cleared the Check Engine light. I kept my fingers crossed and lone behold, the car started up right away. I've been driving the car around and its driving fine and the Check Engine light has not returned. I'm thinking it was the idiots from AAMCO who either by negligence or purpose did not clear the codes after they were done. The net effect is that THANKS to the suggestion for clearing the code, i probably saved myself anywhere from another $1000 to $2000

 

I suspect these were original codes present and they fixed the AT transmission switch (very steep repair price IMO).

The P0420 code is catalytic converter efficiency not adequate, and may return if there is a real problem causing this code. It can take some time for engine computer to monitor system and set this code. Hopefully, you've seen the last of it.

Sorry for your troubles and hopefully they are fully resolved.

good luck