{ENGINE} pulling codes

[Paul_]

1st question? is it possible for codes to repeat themselves?

i did the koeo test and got 91, 41. 91, 41. i'm assuming the 1st set was what the computer picked up immediately and then the second set was in memory.

now for the koer test, i got these: 91, 21, 41, 81, 37, 42, 41, 91, 81, and 37 again. i think i goofed on the 37 because there is no 37 according to my books

now the 41, and 91 codes refer to my o2 sensors. now the code 42 references a heated 02 sensor. whats the difference between a heated and non heated?

the code 81 references air management 2 circuit failure. wtf is that? and how do i fix that?

and code 21 says my cts is fucked. that i understand.

i'm assuming my o2 sensors need to be replaced. i'm just wondering wtf is the difference between a heated and non heated. i always thought it was just an o2 sensor. and finally what the fuck is an air mgt circuit?

and thanks for the help!

[85crownHPP]

I think codes do repeat themselves in sequence, but your seem out of order, hhmm I dunno.

air managment might be part of the smog pump system, but im not sure about that either.

I do know that heated o2 sensors are more expensive than non. lol

sorry i cant help more but ive yet to explore the world of trouble codes...

[88grandmarq]

Yes, the codes repeat themselves. they should be in numerical order.

I would replace the CTS, pull the negative battery cable, step on the brake pedal, reconnect the battery and drive the car for 100 miles
see which codes come back.
Many different problems can cause 02 sensor failures, just because you get a code does NOT mean the sensor is bad.

[Paul_]

i'll do that. i'm still leaning towards the o2s only because i do not know if they have been replaced, my fuel mileage is very shitty(little under 100miles to a tank, even tho sdme of that can be blamed on my dying tranny(tho i believe replacing the tv grommet has extended its remaining useful life abit,lol.)and sometimes the exhaust smells rich, even tho i'm not blowing smoke. before i replace the 02s, i'll follow your suggestion and replasce the cts.

[88grandmarq]

Also check the wiring to the 02 sensors. sometimes they contact the exhaust and get burned, or the harness grounds will corrode and break where they attach to the engine block. The left groud connector is on the drivers side rear intake manifold bolt. the Right ground connector is on the rear of the passenger side head, you can access it from under the car. inspect both of those, I broke the left one unknowingly one time when I changed the intake manifold gasket, caused all kinds of problems.

[88grandmarq]

whats the status on this?

you change the CTS yet?

[Paul_]

nope, haven't replaced the cts yet. i've actually been on a major cash shortage. i was thinking of pulling the one from the Merc tomorrow and see how that one works. my other prob right now is my parents. they want me to stay inside till i'm feeling better, which means i can't work on my cars. sucks to because i have almost an entire weeek ahead of me in which i can get stuff done. but i do believe they have a point since the average temp around here for the past two weeks has been about 35 fahrenheit.

[Paul_]

alrighty, just replaced the cts, and i did reset the computer. unhook negative cable, turn key to on and depress the brake pedal for 10 seconds. we'll see if mr. cel shows up at all. i'm off to work

[88grandmarq]

drive it for about 100 miles and then re-check for codes, regardless if the engine light comes on or not.
My check engine light has NEVER come on and I get codes all the time