Rought idle has been chasing me for a long time now. Engine seems to vibrate too much and sometimes it seems like it misfires, although all 6 coils were replaced with updated ones and there are no codes. Cleaning my TB doesn't seem to help. Overall engine doesn't sound as smooth as before. Any idea what else could cause it?

Also, gas milage seems to go down with every tank of gas. Honestly, have no idea what the cause could be, used to get 280-300 miles on a tank, barely 260-270 nowadays.

Any thoughts on this?

btw, my mods: berk intake with K&N, and FrankenCar catback.

 

Well my gas mileage was going down from the last couple of months and my MAF sensor Just wet out las sunday, so im replacing it tomorrow, and it was idleing rough so i hope this solve the prob ill keep you updated tomorrow when i put it in!!!

 

I was thinking about getting a new MAF as well, but I had this going on for a long time and if it was the MAF I'd expect it to go out by now. Anyway, let me know if a new MAF changes anything for you

 

Go to the SEAFOAM thread and see what we have experienced. No more rough idle, better mileage, better response etc. SEAFOAM is a an automotive engine "cleaner". Try SEAFOM.COM also. Good luck.

 

I'm gonna try seafom soon.

Any other ideas?

 

cleaned your air filter lately?, or injectors? Both of those could contribute to your car's condition.

 

injectors were cleaned and nothing has seemed to change at all. Air filter has about 6-7k miles on it, but I had same issues even before I got it.

 

How did you clean your injectors? Did you just use injector cleaner that you purchase at the autoshops? Those really don't get everything out the injectors, especially if its been a while since you last had them serviced. You might have one that is still bad. You should try doing a fuel pressure test to actually see if they are working properly

 

When using the Seafoam, how did you put it in ( gas tank, throttle body)?

 

Check this link out. He goes into detail. I did it exactly as he wrote it and it worked(s) great. Good luck!

http://forums.maxima.org/showthread.php?t=346574

 

Motor mounts?

 

The Seafoam helped the throttle response, but I still have the same rough idle when first starting unless I let it warm up a little. Any other input?

 

Nevermind, I found a TSB on this site about it.

 

bringing this topic back to life...

thanks for the reply and advice. I used BG 44k to clean the injectors and seemed like it didn't help at all. What are other inexpensive options to clean them? Fuel pressure test sounds good too.

I hope not.