I checked my truck for codes and it came up with these po136, po141and po174 where do I start? Could these be caused from a bad cat?

 

You won't get P0136

But P0141 is the heater circuit for the Bank #1 02 sensor has failed

P0174 is lean on Bank #2

 

Usually you see P0171 and P0174 together which means its running lean on all cylinders. But because its only running lean on one side leads me to believe something on that side of the engine is burning too little fuel. Maybe contaminated injectors.

 

If you remove the O2 sensor near the cat and it performs better, thats the indication of a bad cat.

 

Yeah it came up po136 bank 1 sensor 2 my truck has 2 cats 2 what sensor do I need to remove there's 2 before the first cat and 1 after the back cat?

 

Cause the po174 code be a bad mas?

 

Huh weird P0136 doesn't come up in my list for the 96. Anyways you have 3 O2 sensors on each bank and one near the cat, seeing as there is only one on that bank I'd be inclined to test that one.

You could try cleaning the MAF, but usually you see P0171 too when thats the case.

 

Ok I'll try that thanks

 

I would pull engine vac if both banks are running lean.

 

It's going to the shop Friday I used 1/4 tank in 20 miles !!!