is it ot isnt it
 

i noticed but it does not do it all but most of the time. it will shuder and sound like a back fire coming out of the intake tube.is it the cat that is getting cloged i just want an opinion i just redid the tune up when it first did it also cleaned and let sit the k&n drop filter i just wanted to ask to get the opinion out there. just to look for i dont want to fish around. i checked the fuel pressure and the relay for the fuel pump also had the pressure reg. checked and replaced to see if that was the problem as well to make sure it wasent dumping fuel into the engine while working. it is also a flex type but i did run e85 in it but stoped do to how fast the first tank disapeared when using it. just wanted to throw out what i did so far i hot it is not the trans or some thing else because i did also did a flush as in drop pan and replaced the filter and refill. to make sure it wasent that as well loss because i am unsure to keep a eye on

sorry i thought i was in intake and exaughst but unsure where it should be in

Shake the cat there should be no rattle from inside of it . If its just plugged a shop will probably have to test pressure at the tailpipe. Mass air flow sensor could b getting dirty. It could truly be anything though. Does it happen at a certain time usually? How often?

when i start ip up again when i am leaving a stor or work? it is frustrating because i just cleaned the maf. and getting ready to go to the dentist this morning to get my tooth fixed will check the cat when i get a chance.

I would personally check those nasty e3 plugs you say in your signature. Tjhose are bad plugs and are known for problems like melting. Although they seem good in the start oem iridium acdelco is the way to go.

the e3 are fine the original oem type gave me ignition problems. like missfire from 143 cylender. the stock did break apart when i took them out in my hand back when i had head problems but after that fine with the other type. i had the cat off there was some powdery stuf came out of it i think it is the cat.

I just bought a high flow magnaflow cat today I hope to have it on by tuesday. I've heard good things about them costed, $100 I should get $50 for the old. Your cat should never be powdering out. Sometimes cat failure is caused by fuel not being used I.e. misfires, or just tons of bumps overtime.

i know i did have a terreble missfires i replaced my coil pack twice because of it do to both ironicaly going bad do to gremlins. thats what i was thinking do to the missfires fuel not properly being burnt fouling out the cat. i am just mad because fixed the issue of the missfire and not fireing and doing a dump i didnt drive it that much do to it but irony has to play in a way. where did you get yours mwjames i am wondering where to get one to fix the problem. right now when i shook it to get it all out it seemed to clear up but i dont want it to cause a problem with some thing else