Cypress123

It had no thermostat, now it comes to temp 192°, but still shows the i/m catalyst yes and a 430 shows at the same time after a 4 - 5 mile drive - others don't decide catalyst that fast ? ? Could someone have messed with the programming ? if so, can I see that with the scanner ? - so is it another PCM/ECM, or the right catalyst ? ?

tech2

the cataylst monitor is comparing cross counts of the front and rear 02 sensors for that bank. if the 02 sensors are switching normally you need cat for that bank. just make sure you don't have a new 02 on the rear with a old 02 on the front.

Cypress123

OK, ordered 4 new O2 sensors they should arrive in about a week - sure glad to get good advise ! sorry we lost the thermostat bet ! Perhaps I should drive it longer and see what all codes come up later ?

tech2

i was not recommending replacing all the 02 sensors but rather make sure they are switching...ie cross counts.

Cypress123

Ah OK, so maybe I need to look for a Y pipe or cat ?

Pulled the bank 2 sensor 2 and found the last mechanic had plugged it in with a bunch of crud in the connector, washed it out and installed again, no change, same low cat bank 2 and cat cleared Yes, drove it about 15 miles, no other codes - Looking at the constantly changing read of the 1st and 2nd sensors, I'd guess them to be about the same - any point to install the new o2s ?

tech2

the front o2 should switch fast...the rear slow....if they both swiitch fast the cat is not reducing/oxidizing or storing ox ygen....so the 02 in the back is reading the same 02 content as the front
so if the both are switching fast...they are probably ok and you need a cat.

don't cheap out....a cheap weld in cat has low cerium content...the oxygen storing element....a cheap cat will res u lt in a low efficiency code.

Cypress123

thanks for the advise, I knew there was a problem in the cheap cats but didn't know what it was, I'll look for original parts. A friend on a vacation got a catalyst code on his S-10 he had a muffler shop weld in one, by the time he got back home, he was getting the code again.

Thanks, a lot always good to further one's education !

Cypress123

i cut out the right cat, it is a see thru, no honey comb, good reason to get the code. i can feel something in the left it feels like honey comb, should I just stuff a wasp nest in the right - I assume the last 'mechanic' would have done that..

thanks for all your help !

tech2

do you have emission testing where you live?

Cypress123

Yes this is in Houston's outer edge, they accept one incomplete, that usually is the evap - with the cat replaced things look more normal but not ready for the inspection yet - I'll resume this Monday