Check Engine Light - Automatic Reset?

evrybody thinks that the skys are Sooo much better in LA (and manyother cities) than they were in the 1970's because of the smog devices on cars.
That is totall bullcrap
fact of the matter is that it is because they closed down the local electricity plants that were running on local HIGH SULFER crude oil the municipalities like LADWP were getting for almost free oil from local wells and dumping massive amounts of pollution into the air.
burning all of that high sulfur crude was making everyones eyes and lungs burn
blamed it on YOUR car instead of their greed and stupidity
Then they fooled everyone into thinking the BS piddly smog devices on cars came to the rescue.
Everyone was fooled
it worked great and justified the EPA and CARB scam that continues today
we are so fricken stupid , the government has us so scammed and beat down its pitiful

 

Are you one of those people that say human caused climate change isn't real?

 

Not it

 

Kinda forgot about this thread. I got impatient waiting for the code to self clear, so I ended up clearing the P0120 code manually, then restarted the drive cycle. Amazingly enough, it only took a couple of days to set my readiness monitors this time. MUCH quicker than before, for some reason. Anyway, I was now free of stored codes, there was no CEL on and my readiness monitors were all OK. I was pretty confident I would pass my smog check now, (though less confident that my P420 code problem was permanently solved). So, I got my smog check and the guy told me I failed, because my aftermarket cat convertor model number was not approved by CARB for my Tacoma's "engine family". Apparently there are two engine families for this vehicle...the more popular "R" version and a the less common "H" version. My Tacoma is the "H" version but my aftermarket cat was for the "R" version. How the previous owner passed smog with the wrong cat is unknown. Either he bought off the smog tech, or the smog tech wasn't very thorough. At any rate, I was forced into removing my two, probably perfectly fine cats, and putting in two brand new aftermarket cats at a cost of $600 total. Got my smog check right after that and passed with no problems. What a friggin' headache.

In answer to your question, there is a specific drive cycle for each of the monitors, published in a Toyota TSB. In theory anyway, if you drive exactly accordingly to the drive cycle conditions, you should get a READY status right away. In trying to set my CAT readiness monitor the first time, I drove exactly per the drive cycle, but it neither set or turned on my CEL. Oddly enough, when I last reset my stored codes I didn't pay any attention to the drive cycle conditions, and the readiness monitor showed OK after just a couple of days of normal driving. Go figure.

I will say for anyone who has a persistent P420 code and needs a smog check, be sure to try using a bottle (or two) of Cataclean ($25) before doing anything drastic like replacing your cats. Two bottles of it kept my CEL off for hundreds of miles, and I'm confident I would have passed smog check had I not had the wrong cats installed.

 

Thanks for the reply and information. Sorry to hear about your cat issue, another thing to look out for here in the golden state.

I've always had pre-smog diesels, so this is my first smog experience. I'm gonna put 150 miles on it this week and try again.

In other news, I cleaned my MAF, it was very dirty, it took 3/4 of the can to get it clean using short bursts. Now my hot and cold idle is a couple hundred rpms lower, Also removed and cleaned the intake up to the throttle body I drive on dirt roads and a poorly fitting filter allowed some dust in at some point...