2003 Navigator P0175

[96mustangV6]

Ok, so I've changed all 8 injectors with new Injectors, Put all New Plugs In, Cleaned Maf, Cleaned IAC and still getting a p0175.

The truck Dosnt run rough or anything. Get bout 15-16 mpg on highway and running 91 octane. I'm confused on what else to try.

The old plugs were clean . Not one plug was black or had signs of running rich.

I did notice the intake smelled like gas real bad though when I pulled it off and had a residue on it.

It takes about 1-2 weeks for code to pop up. I can clear it and same thing.

I'm going to clean throttle body next but what else can I try.

I was getting a p0171 I believe it was before injector and plug change but hasn't popped up again.

It's a 2003 Navigator with the 32v 5.4. Has 160,000 miles.

 

[toms89]

Ok, so I've changed all 8 injectors with new Injectors, Put all New Plugs In, Cleaned Maf, Cleaned IAC and still getting a p0175.

I did notice the intake smelled like gas real bad though when I pulled it off and had a residue on it.

If the intake had strong fuel smell, or puddling of fuel I would check fuel pressure regulator vacuum port. The diaphragm can rupture or get pinhole in it leaking fuel into the vacuum port thus intake. I say this because I had this happen with my mustang.

A quick test would to supply vacuum to the regulator via your mouth and some vacuum hose. (carefully of course) If you taste fuel you know it leaks. If not it should be ok.

 

[96mustangV6]

That sucks if so cause the regulator was part of the rail. I will have to replace rail. How come it's just show in bank 2 though. The regulator is on the passenger side.

It's cold here so be a few more weekends before I can try this but will try it.

Anything else I need to check.