This morning I noticed that when I was going 60km/h (40mph) there is a very very slight pulsation/hesitation I can feel. Almost like a very small faint misfire. I couldn’t tell if it was just the road or not. But after some driving I can tell that it was in fact a pulsation and not the road. After cruising at that speed for about 15 minutes the Check Engine light came on. I plan on getting the code read but in the mean time anyone have ideas? The only thing I did in the recent past was gap my plugs a little small when I replaced the IT-22’s with new ones. For some reason this time I decided to gap at .034 rather then .038. Could this cause this problem?

I am thinking maybe a bad coil or maybe an 02 sensor?

PS, The truck seems to run fine other then the problem above. It seems to have good power and accelerate smooth at any throttle position.

Mods: 6# pulley, Diablo chip, Airaid intake, FTVB, Denso IT-22's, Oil seperator.

Cheers, Jason

 

Sounds like it could be the EGR. Check the plastic line that goes to it and make sure it didn't melt on the EGR tube. If it didn't try unplugging it from the EGR and see if it goes away.

 

I had a similar situation happen a couple of weeks ago. My truck started to "chug" a little at a steady speed and it started to idle a little rougher than normal. Eventually the "Service Engine Soon" light came on. Plugged in my Predator and it was a P0402 Code - EGR- Excessive Flow Detected. The dealership ended up replacing the DPEE sensor.

I also had a rattling noise coming from the engine compartment. That turned out to be a bad tensioner on the drivers side timing chain! There was basically no tension at all on the chain. This may have also contributed to my rough running condition. I pick up the truck tonight - hopefully good as new.

NTIMD8 - hopefully your issue is just a sensor.

 

sal hit this one on the head, same symptoms as me just unplug the tube going into the top of the egr and plug it, mine didn't hasn't set a code yet with it plugged but i have only been a few miles, what is the best way to clean it?

 

I agree with Sal & Bryce, I feel it's the EGR sensor the condition you are discribing is called trailering. What it means it's like if you were pulling a trailer.

Suavy

 

would there be any effect on fuel mileage with the egr vaccum line plugged?

 

IMO, I would say it should not. I have read of a few people not using the EGR tube at all.
I can ask the dyno tech tomorrow if you'd like.


Suavy

 

Thanks for the info guys. I will try this for sure and let you guys know.

 

Had exact same symptoms on my 2001 - problem was bad EVR (electronic vacuum regulator) selenoid -

 

I did this as well to cure the described symptoms. I disabled the system with the vacuum hose plug method.

My Gas mileage has dropped between .5 to 1 mpg by doing this. And it threw a code. I wish I knew what exact part to replace in the system so I don't have to buy all 4 components. I might try the EVR selenoid as mentioned.

In any event, it runs good now which is the main thing.

BD

 

On the EVR itself theres a round cap that can turn under this cap are two foam filters ,Mine will run rough once ina while and with the engine running I can move this cap an tell right away that the engine will run smooth again