Hello. First post here. Looking for help/ideas for my 98 blazer.
Drove great until I started getting egr codes. Finally figured out the cat was plugged causing back pressure.

Drove fine for a month or so now it's acting similar. Finally gave me a code on the freeway for tps. Replaced. code gone drove a little better. Replaced fuel filter drove a little better for a day or two.

after this I decided to just drive it since if I drive like an old man it's ok and drives normal. Certain times from a stop it would shudder like it was about to die.

Finally 2 days ago I get a code for cyl 2 misfire. Just replaced plugs, 1 was arcing through porcelain, 2 was gapped wrong >.060, distributor cap was missing the rear screw and was crusty, rotor was crusty. So I changed all the plugs, wires, cap, and rotor. Gapped to .060 per the emission sticker. It does run quite a bit smoother. Still having an acceleration problem if I try too fast. Replaced the pcv valve 5 mins ago but the hose was old so it broke of course. Now I'm waiting to pick up some hose so I can finish that. The one I pulled did pass the rattle test and didn't look horrible. So I doubt that's gonna change anything.

off the line it will get up and go. If I slow to take a turn then try to get on it or speed up to pass someone is just kinda sits there for a few seconds and then slowly picks up speed and rpm. Now it will do this faster if I back off the gas a little. I'm kinda at a loss now. Anyone else come across this issue?

170,000 btw.

 

Try cleaning the MAF sensor. It will give symptoms as you described.

 

Thanks. Haven't cleaned it since I've owned the car. I'll pick up a can today.

 

Update: installed new pcv valve and hose. Cleaned maf. Drove worse today. Had trouble doing speed limit on freeway (65) I have a sneaking suspicion that the catalytic converter is about to **** the bed again. I'll try a back pressure test again tomorrow when I get to work. Throttle to the floor on freeway hit 55 and losing speed. No codes.