tahoeman1996

Hey fellow chevy lovers here it goes....my hoe broke down after the service engine light came on on the highway (how it shut down the way it did I thought something major) so hoe down 4 a bit have spark/fuel but wouldn't fire up,I know strange huh.towed 4 the first time since I've owned her fer 4 years,shop said she needed a tune up so she's a typical old girl and got what she needed lol got er running they cleared codes ran great for a couple of days even treated her to a full tank of the goodstuff and a fresh flowmaster exhaust.so a days go by and I start feeling a missfire on the highway at about 65-75mph not really noticable at city speeds unless rpm's are wound up tight after bout 100 miles from getting the tune-up the service engine light comes on again (here we go again) this time stays running and runs a bit rough at idle nothing terrible but I feel it so we go straight to the part store so they can pull codes for me and we had 3. P0102 maf sensor fault p0300 multiple cylinder missfire and p0430 o2 sensor fault bank 2 downstream now no biggie called shop for advise I was told that if I replaced the maf sensor the other 2 would correct itself,so I did the maf sensor reset the codes everything is good woo hoooo,ooooops 2 soon about 40-50miles still noticing the miss fire on highway and low and behold the service engine light on again, go back to part store and got the code p0300 again other 2 did not show again. Not really sure where 2 go from here without aimlessly replacing components , I talked 2 few fellas I know and I'm bieng told coil packs,crankshaft sensor,camshaft sensor, map sensor, fuel pressure regulator as the pump is only about1 year old and again my better judgement aftermarket...any advise is greatly appreciated

jeffsw6

Hopefully your new air cleaner was over-oiled and simply fouled the new MAF. Before throwing a lot of parts at it I would change to OEM air cleaner and ask parts store to clean the MAF you just bought or exchange it for another one.

You will sometimes read debate online about those aftermarket air cleaners. They are a scam, all they do is cause people problems like this. My $0.02 anyway.

inthechateau

Take a close look at your rotor button. Had one last week with the mul;tiple mis fire and turned out to be a crack in the rotor button from one of the mount screws. Did not need the cap just a new rotor, runs like a screaming eagle now. ++ on the over oiled filter. i run the Nolant Cold Air Intake suystem and over oiling will cause problems.

tahoeman1996

Thanks for the reply guys i will will look into the rotor though im not to sure my 96 has one looks like it has 2 separate coil units each with 4 plug wires on em but ive never really paid them any mind as its had 2 tune-ups and they have been just wires and plugs if any else has any ideas as to get here purring again properlyplease feel free any advise appreciated. i get home on weekends (truck driver) and will most definitly will be everything and anything to get her standing on all 8 again lol thanks again

tahoeman1996

Uh oh sorry jeffw6 I hear u on the aircleaner deal but I'm running the stock box and filter tho, I was gonna go 2 aftermarket but after reading a few threads on here I decided against it lol but please if u can think of other possibles feel free.thanks again

sfcjones

I read a report a couple of years back and I decided right then to take the K&N filter setup out of my truck. I went back to stock because it flowed as well as the after market and I didn't have to oil it and worry about the amount of debris gong in before it started filtering like a stock paper filter would. I think they are a scam as well and would never waste my money on them.

tahoeman1996

ok fellas i just got home and looked under her hood and realized i'm an idiot....it does have a cap and rotor that is so definitly needed so she got the new parts.absolute full tune up now plugs,wires,cap,rotor etc... she still burping (missfiring) like crazy checked firing order and all is good there,someone please point me in the right direction i'm at a complete loss here thanks for any advise in advance

inthechateau

With it running I'd start pulling off one wire at a time to find cylinder at fault. Possible not ignition, could be poppet valve in injector unit.

legolas894

Did you replace the catalytic converter when you put the flowmaster exhaust on? I had a Park Avenue that ran fine around time but had issues at highways speeds. Took a lot of troubleshooting and then found one guy who said "plugged catalytic converter". Fixed that and it screamed out of the parking lot after that. Maybe a different back pressure from factory causing a problem. Just guessing....

tahoeman1996

Thank you guys for all the great responses... I did a. Little more digging on the whole injector popppet issues with the csfi beast and I believe that in my opinion that is my logical next course of action...when I get home this weekend I'm gonna order everything I need for the csfi to mpfi injection conversion kits with all the goodies, I am hoping to get it done by my own wrench in the next week or 2 but I will post where and how the parts will cost and most importantly if it corrects my problem when it finished...thanks again fellas and again i'de do about anything to keep the old girl going lol will keep u posted