97 Rodeo P0300 random misfire

[todds21]

I have a 97 rodeo v6 with 110K on it. I am the original owner and have done all maintinence and run synthetic oil in it. The CEL just came on and started running rough with no power. I just had my shop replace the 02 sensors and they did a injector flush. The CEL is still on and the shop thinks its an injector problem but said try to run a couple of tanks of gas with injector cleaner to see if that clears it up. The light blinks at about 2500 rpm while driving. Anyone have any ideas why it may be misfiring and if I should just bite the bullet and take it to the dealer? It has been a great truck so far and I am hoping for lots of miles out of it. I took it to autozone and they said the code was P0300 random misfire. It starts fine no problem.

[rodeo02]

Random misfires can be a challenge . I would suspect a vacuum leak, maybe a MAF sensor issue, or possibly the EGR valve pintle is stuck open causing excessive EGR & air/fuel ratio issues. Search around the common chamber for a loose vac hose or blown gasket, check the MAF sensor for dirt, and pull/clean the EGR valve. Ive had a few older cars well past 100K miles & have never had to have a *fuel injector service* done, so I'm not a big proponent of those. Also, NEVER let anyone changeout O2 sensors for you unless you are getting a slow or no activity code from them. Big waste'o money.
G/luck!
Joel

[todds21]

I am using the AMSOIL oiled filter. I saw on another post that the oiled filters could cause fouling of the MAF. Anyone have any guesses if this could be the likely cause?

[rodeo02]

Originally Posted by todds21

I am using the AMSOIL oiled filter. I saw on another post that the oiled filters could cause fouling of the MAF. Anyone have any guesses if this could be the likely cause?

Most definately! I've seen this time and time again with oiled/reusable air filters. IMHO- they do more harm than good in a modern passenger car application. Get a spray can of electrical contact cleaner (radio shack or the likes) and some cotton swabs to CAREFULLY clean MAF probe wires.
G/luck
Joel

[todds21]

I cleaned the MAF probe wires and reset the computer. The check engine light did not come on idling in the driveway warming up. I made it a couple miles and it blinked and then the solid CEL. Thanks for your help Rodeo02.

[2eyefishclaw]

you say all of the maintenanace is up to date
that must mean that the spark plugs have been
replaced
use NGK in this vehicle if thats not whats in it and your problem should be gone

[todds21]

Originally Posted by todds21

I cleaned the MAF probe wires and reset the computer. The check engine light did not come on idling in the driveway warming up. I made it a couple miles and it blinked and then the solid CEL. Thanks for your help Rodeo02.

I replaced the plugs with Platinum tips at the 60,000 mile maintinence with the timing belt and everything else. Is the 97 real particular on plugs too? I smelled alot of gas this morning when it was warming up. Not sure if its just running real rich or problem with fuel system. It has not stalled and starts fine. Just has sluggish response and CEL. Thanks for all your help. This is the best resource I have found.

[2eyefishclaw]

platinum will work but what brand did you use if its BOSH its garbage and I am 99.9999999% sure if its bosh you have in it replacing them with NGK plugs will cure your Rodeo