I have had 3 5.5 gen Maximas in the past year. All of them had an NWP BOP installed. The first of these 3 Maximas never gave me a code, but my last car and current car throw a p1800 code. The current one will not go away.

I have been searching the forums last couple days and followed all suggestions I found but nothing worked. About 2 weeks ago I had a random misfire that was fixed by changing the PCV valve and hose. The car drives AWESOME and doesnt have ANY hesitation.

What could be wrong? any ideas?

Last bit of info: I got the NWP Engineering Intake Spacer kit installed too.

 

No one? I did quite a bit of research. Checked every p1800 code thread and bop thread on here.

 

I read on here somewhere that the MAF could MAF a false or ghost code. They recommended replacing it with the 2000 maxima MAF.

 

I read that too. Will all 3.0 mafs work? Is it plug and play?

 

Try putting the stock plate back on and see if the code goes away..

 

Have you tried installing a known good VIAS solenoid and clearing the code to see if it comes back? Make sure the electrical connector and wiring on the VIAS solenoid is in good condition. I'm guessing the solenoid is bad or the connection is corroded.

 

i did try replacing the solenoid. I had 2 totaled cars but only 1 i knew for sure had a good vias just dk which i kept. code did come back. wouldn't that throw a hard code instead of a pending one tho?

 

Not sure. But something is up with your connection or the wiring. I would get a multimeter and check to make sure the the voltage is correct at terminal #27 of your ECM. While at idle, it should be battery voltage. If it's less than 12v, I'd find out why. It could be due to corrosion. When you rev the engine between 1800-3600rpm, it should be 0-1v.

Improper voltage to the ECM is the only way you can get this code and that can only be caused by a faulty solenoid that has shorted out or a wire that is corroded, open, or shorted.

Start by cleaning the VIAS solenoid connector with electrical contact cleaner and scraping it with a flathead screwdriver or small paperboard nail file. Try to clean the male and female connectors really well. Then inspect the wires for any nicks or cuts. If all that is fine, see what voltage you have at terminal #27 of your ECM while the engine is running.

 

Thanks for the response Aaron! I'm having the same code and it started prior to the BOP.

@ OP, I researched this code as well and came across the 2000 MAF swap thread: http://forums.maxima.org/5th-generat...-pictures.html

 

i didnt see any corrosion on the plugs to the solenoid but i cleaned it anyway. both sides. tomorrow i will check the codes and update this thread

 

So i just checked the codes and erased p1800. It comes back immediately doesnt matter if my cars on or off. Still comes back. Always pending

 

I just wiggled the wires to the maf and the wires to the vias solenoid and erased the code and it didnt come back this time. I also noticed a little slice in the harness to the solenoid. Could this be causing it?

 

On the maf i just unplugged it and reattached it. I didnt wiggle it.

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