ok, so another CEL. these are the codes to pop up. They are both EGR codes:
0705 --Diagnostic Trouble Code 0705 points to a problem with the Evaporative Emission Control System. and
0903--Diagnostic Trouble Code 0903 indicates a problem with the Evaporative Emission (EVAP) Canister Vent Control Valve or its associated electric circuit.

i just bought it and had the knock sensor and o2 sensor replaced. after spending 6k, i gots to do it myself. so... any ideas where to begin? any help appreciated.

 

Easy fix and won't cost you more than 75 bucks even if you have to replace everything.

The EVAP Canister and Valve are behind your drivers side rear wheel. There is an access panel there with a couple of plastic clips in it.

The Valve is kind of a pain because the hoses are pretty stiff - but you can see it attached to the canister once you get the access panel off.

You can do one of two things. Try pulling the valve assembly off of the canister and cleaning it with some WD-40. Work the valve back and forth while spraying liberally. Clear the code and reinstall... that cleared my code for about a week. YMMV

Or, you can order a brand new cannister and valve assembly (if you get the valve - get the cannister, it isn't that much and you're already in there so what the hell). From Courtesy Nissan, I think I paid 75 bucks with shipping. Took me about ten minutes in a parking garage with a flashlight to remove and reinstall.

If you really want, you can drive it to my house in Salem - and I'll show you what you need to do. I am probably an hour away.

HTH

 

would this account for some power loss too?

actually, im south chicago burbs, around indiana, prolly take me bout 2hrs to hit WI on 94. thanks for the offer tho.

 

I have the same codes. This was the preferred fix- just replace the parts.

After that, try a BM emissions system flush to clear out the gunk that caused it in the first place.