I Have a 2000 blazer ls 2 door 4x4 and have done much work to it and recently have been having power problems on take offs mostly when the engine is cold. i am showing a 02 censor post cat bad. fuel pressure is fine no problems starting ,
the work i have done is
...
intake gasket .radiator . wheel bearings. fuel level sensor. muffler. brakes normal maitannce fuel lines , fuel filter, and much more i have owned it for about a year now and just want a reliable truck . it has 113k miles let me know what you think about my power problems please.

 

your cat might be clogged . check it out

 

That was my next step . thank you for reasurring me .

 

Yeh warm your blazer up real good at night and look at your cat. It usualy glows red hot when clogged. (well at least the times ive ever came across that prob in the past)

 

lol mine went up on fire

 

Or do what the shop does (if you have a good hand held temp reader) warm your truck up for a while then take the temp of the front of the cat then the temp of the back of the cat. If the front is quite a bit hotter then it's clogged. When mine was clogged it was like 260 in the front and 220 in the back which is a big over the length of the cat. Or have a shop test it, most do it for free.

 

one other idea... when my Mass Air Flow meter went bad the truck accelerated like crap off idle. A good scan tool showed my fuel trims were all out of whack. A simple test is to just unplug the MAF and see if it runs better. If it runs better unplugged, that may be your culprit.

 

although when i unplug the maf sensor the truck wont run. im almost sure its the cat . im gonna put it in the air tonight.
thanks to all of you

 

If you are disconnecting the MAF with the engine running, I would expect it to die. It should start & run with the MAF disconnected though.

 

Call me crazy, but explain why a temperature drop through the cat would signify a clogged cat? Personally, I would pull the up steam O2 sensors, or better yet, plug a good old fashioned vacuum guage into the motor and look at the vacuum its pulling.

A red hot cat should only show that its burning off unburnt fuel. Correct?

If Im off base here, please educate me.