Im having a problem with my Blazer. it starts up great and idles well, but when it warms up after about 10minutes it gets alittle rough and shaky. then it will start to sputter for a second then clear up. How ever if i get on the freeway, i still can accelerate up to speed but my rpm gauge doesnt really move from about 1800 unless i floor it.

Ive already replaced the Fuel pump(it went out earlier this month), fuel filter, fuel pressure regulator, IAC sensor, MAF and full tune up ie.(cap, roater, wires and plugs.)

I need help, can someone please give me some ideas?

 

Check the coil and module. My pig tail wires going to the coil went bad and had to buy a new one. You can have the module check at Auto Zone.

 

How many miles on the catalytic converter? Sounds like it is clogged-up. Pull the O2 sensor out and go for a drive.....the Service Engine Soon lite will come-on, but if if runs better...you have found the problem. Go to AutoZone and they will clear the code and turn the SES light off.

 

i have about 150k on the truck and still have the original Cat. How much are they if i need a new one? id like to not spend another $700 to get my car running great again. Would the O2 sensors be messing with my mileage has well? im getting about 25% less then i was before i replaced everything.

 

I just bought my Cat. from Summit Racing for $ 362. shipped direct bolt on from the exhaust manifold to the muffler.