O2 sensor

95s10blazer · June 19, 2002

I have a 95 S-10 blazer and my check engine light has come on and i read the code and it said running rich. i erased it and it came on again and it was the second O2 sensor so i replaced this sensor due to a check engine light a month ago and now replaced again because it was black it obvioslly is carbon build up but any reasons why i am running rich and causeing carbon to build up on my second O2 sensor would be appreciative

95s10blazer · June 19, 2002

My buddy thinks it might be the cat conveter getting ready to go

Frank S · June 19, 2002

I dunno how you're truck is set up but My 2000 S10 has 3 oxygen sensors.

I'd check and see if your's has that 3rd sensor before anything else if I were you.

Welcome to the board btw.

bowtie_pasta · June 20, 2002

You know, not to alarm you or anything, but I've heard the the 95's have some type of known problem with the intake/fuel injection system. When I say known I mean GM released a bulletin/notification on the trouble.

My neighbor has a 95' and had to have about $600 worth of work done to his.

Hopefully this is not your trouble though. I specifically stayed away from 95' when I was buying my truck.

Anyway, best of luck! :sideways:

95s10blazer · July 8, 2002

OK guys first off on 95's do not have a 3rd O2sensor second I am getting ready to replace my 2nd O2 sensor for the third time. I stopped down to the local chevy dealer and talked to them they said for my to lift off the upper intake and see if gas residue was under there if so to repalce the CPI he went on to say that 95-98 this is a common problem and is around 600 to fix just wanted to see if thats what your neighbor had to replace this problem is driving me nuts thanks for all your help so far. ???

bowtie_pasta · July 9, 2002

I'll ask him when I get a chance. I can't remember the exact work that he had to have done.

I'll try to keep you posted.

96 Noma · July 10, 2002

OK guys first off on 95's do not have a 3rd O2sensor second I am getting ready to replace my 2nd O2 sensor for the third time. I stopped down to the local chevy dealer and talked to them they said for my to lift off the upper intake and see if gas residue was under there if so to repalce the CPI he went on to say that 95-98 this is a common problem and is around 600 to fix just wanted to see if thats what your neighbor had to replace this problem is driving me nuts thanks for all your help so far. ???

What the dealer said was correct. The 95 CPi injection unit is notorious for leaking. At least 65% of all the onwer exceeding 75,000 miles have ahd this exact problem. The only way to check is just the way the dealer said, there will be puddling of fuel when you remove the upper intake and they only way to fix this without altering for a different fuel system is to have it replaced and $600 is the average.