jcolegrove

I changed the whole shebang on my '92 LS 135k-- tim belt, water pump, distr, wires, plugs, idlers, etc... all OEM stuff. Started and run perfectly. After driving a few minutes CEL and TRAC off comes on. CEL code is 25 and i have factory book. i did some electrical testing per the trouble shooting and nothing definitive came up, though the two O2 sensor readings were not the same and so i have one of those coming...
my question is, this 25 code lists about 10 things that it could be. O2 sensor is one down the list. fuel injector leaking, tim. belt skipping teeth, etc.. is others. IF i had put the belt on wrong (and i'm 99.99% sure i didn't as i checked and checked and it wasn't a prolbem and the car runs perfectly, etc..), would a tooth off cause drivability problems? is it obvious when the belt is on wrong, even by one tooth?
then secondarily-- how weird it came on after the work-- apparently i did something somewhere. the O2 sensors are orig. at 135k. thoughts please? thanks.

Bali26

If the O2 readings are not the same and they are originals, I would change em.

Just get walker 4 wire universals.

skipped tooth would surely cause bad idle and more.

etex

Did you change the timing belt tensioner? Sounds like it could be loose.

jcolegrove

yes, thanks- forgot that. i DID change the tensioner, too.

python

iTrader: (4)

is this the NO RPM SIGNAL code? if so u have the belt one tooth off

jcolegrove

no- only code 25 and the trac code, which is triggered from the code 25 engine code.

Zero_One

iTrader: (1)

25 Is a "Lean" code. You are correct, there are a lot of things that can cause this code...valves being out of spec is one of them..i.e. adjustment, or being off a tooth.

I wouldnt change the O2 sensors just yet. If you have one side (bank) off a tooth this could cause a difference in readings due to you not getting the right mixture/burn from the bank that is off versus the bank that is. I would say to check your marks again and verify you are on 100% without replacing anything yet.

python

iTrader: (4)

lean code is usually an 02 problem..b4 the cat, having this problem after u did the belt and not before brings up a red flag tho...

Zero_One

iTrader: (1)

As I mentioned above, the factory manuals suggest a lot of other possible causes before it suggests O2 failures. Check the t-belt and keep us posted. I have seen so many customers waste money just throwing parts at an issue.

jcolegrove

ok- so i figured after 165k on orig. O2 sensors, switching one was not really wasting money, so i switched the one that was not testing according to spec per the manual and voltage, etc... i was cheap and did just one on pass side before cat. it fixed it as there is no more CEL. coincidences... perhaps, though, the new caps, plugs, etc. were making it run a bit more like it should and the used sensor didn't follow suit.... mixing old and new spec parts.

moving on now to the 'trac' light that came on after the above fix...