1999 blazer running rough. need help!
 

i have a 1999 blazer, 2wd, 2door that runs and idles fine. but when i floor it or try to hit the passing gear it bogs and hesitates feally bad. starts to to backfire sometimes too. only thing i can think of is i had to remove the cat. converter and put a straight pipe there. fuel pressures around 53-60 psi. what else should i check???

Are there any codes either stored or pending?

When was the last time you did a complete tune up? If recently, what brand of parts were used?

Have you cleaned the MAF sensor or EGR valve (both covered in the Tech Article DIY section)?

no theres none stored and i did a complete tune up plugs n wired two months ago. cleaned the maf sensor with the crc maf cleaner. i just cant narrow it down...

used bosch plugs and duralast wires.has a k&n cold air kit and i cleaned and oiled it.

With an aftermarket, oiled air filter, the MAF sensor can get dirty very quickly. This is especially true if it is over oiled. When I was running K&N filters on MAF equiped vehicles, I would clean the MAF 500-1000 miles after installing and/or cleaning/re-oiling the filter as this gives the filter sufficient time to shed the excess oil.

When you did the tune up, did you replace the cap & rotor? Wires typically don't matter when it comes to the brand, but plugs, cap, & rotor definitely have an impact on performance in these vehicles. AC Delco has shown time after time to be the best when it comes to these ignition components. Many members have done tune ups with other aftermarket brands and thought they had ruled those components out as the cause of their performance problem. After spending countless hours & dollars chasing a problem, they replaced those 'new' aftermarket components with AC Delco and fixed the problem.