Help me diagnose a check engine light for a patch and my eternal esteem!

Check Engine Light/ Catalytic Converter: A while ago my 97 V6 XLE Camry's check engine light went on and the guys at the dealership who ripped me off to diagnose it ($100) explained that it was a bad catcon. I replaced the part (with much sweat blood and tears) and it solved the problem (light went off) and the vehicle passed emissions testing. Whohoo! Only now the light is back on and I am not savvy enough to just figure it out and not rich enough to buy the diagnostic testing device or to take it back to the dealer. Anyone know of a good way to diagnose for cheap?! 

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Re-design6 years ago
You can reset the light yourself by disconnecting the battery for an hour or so. That SHOULD clear any and all errors.

The check engine light may not be on for the reason you think. So if it comes back on you should have the code run by one of the free methods.

But be aware that disconnecting the battery will reset most radios presets.

And will reset the engine control and transmission control to fact preset.  But after driving 10-20 miles those settings will set themselves to your driving style again.
This is the best method to reset those darn dashboard lights! Some people leave the battery disconnected for one whole night to reset their car computers.
jeff-o6 years ago
I found this information on resetting a 99 Camry, perhaps it applies to a 97 as well.
There may be a second catcon that needs replaced. There is usually one near the catalitic and on on or near the exaust out of the block. I have a simular problem with a Impalia.
NachoMahma6 years ago
. BTW, as far as resetting the errors, there is usually some combination of turning the key on and off, pushing the brake/gas pedal a few times, &c that will reset everything. You may be able to get the brain to flash a code using one of the dash lights. Google is your friend.
Autozone will plug in a scanner for you; they can shut off the check light too. It might just need a reset after the part replacement.
NachoMahma6 years ago
. A lot of automotive parts stores will loan you a scanner that will tell you the error code and reset the brain if needed. You can do it in the parking lot in about 2 minutes. You'll probably have to put down a deposit, but you should get most, if not all, of it back when you return the scanner. Some scanners will have a book to look up the error code; if not, look it up on the Web.
Those who won't loan you one will often rent you one for $15 or so. In fact, I've seen one marketed specifically for that market -- customer plugs it into their car, it downloads the information, customer brings it back and plugs it into the parts shop's PC and the information is read and interpreted.

Also, remember that you usually DO NOT HAVE TO GO TO THE DEALER -- most mechanics now have scan tools and have access to most or all of the same information about how to interpret the results.

The main advantage of going to the dealer is that if something particularly weird is going on, they may have seen it more often than a generalist mechanic would have, and they may know of "silent recalls" related to it. On the other hand, independent mechanics may be more motivated to consider alternative solutions which might save you money, and are willing to put in second-source parts when appropriate (which are often just as good -- part of what makes a good mechanic is knowing when that is and isn't appropriate).