New 1998 QX4, many codes, HELP PLEASE!

[kerberosv2]

I just got a 98 QX4 and have a few codes. I have a P0325, P0300, P0141, P1444, P0325pd, P0300pd, and P1444pd.

I know more than likely, a few of these are related to the same cause, but I don't know what cause that may be. I am new to Nissan/Infiniti, and I know little about them. Any help in diagnosing this issue would be greatly appreciated!

I will point out that it makes no strange noises or knocks. Only thing I notice is that the AC does not work.

Thanks in advance!!
Kerb

[Slumpert]

Okay so the P0300 codes relate to air leaks, poor fuel supply, bad spark plugs, and possibly even bad flywheel or crank sensor
P0325 is knock senor
P0141 is rear oxygen sensor
P1444 is a EVAP valve.

So P0325 is a common issue that is very time consuming to repair. I think the average is something north of $800 in labor alone. There are bypass options that some have done and this code will not cause you to fail a inspection nor will it turn the check engine light on by itself so many never fix it.

P0300 and P0141 could be related. If there are bad sparkplugs / wires esp #6 on the right side then too much gas/oxygen is getting into the cat and causing all sorts of problems.

P1444 could be as simple as just the selenoid itself or in my case the previous owner overfilled the gas tank to the very top so many times that raw gas went into the canister and ate away the foam holding the charcoal in. Which would mean there is now charcoal flecks all inside the evap lines. Disconnect a few evap hoses and see if little blacklike sand is in them.

[kerberosv2]

I was told he had to have the Cat hollowed out rather than pay for a new one. Which of these codes can be attributed to that?

As for the others, it looks like the distributor cap and wires are newer. Maybe they messed something up?

Today under the hood, I notice the air intake "boot" is broken and taped to the air intake. One of these codes attributed to that?


Thanks for all the help! I really hope I can avoid that costly repair you mention. What is the "work around" you are thanking about?

Thanks again
Kerb

[Towncivilian]

P0325 is likely caused by your P0300 (misfire) code. Don't worry about that unless it sticks around after the remaining codes have been solved.

Check under your distributor cap for excessive dust build up and spray compressed air under there to blow it all out. Also see if the rotor is excessively scorched.

Try to inspect for intake air leaks; spray a can of brake cleaner around the intake plumbing and vacuum lines, and if engine RPM rises, you've found a leak.

[Slumpert]

The 0141 code would be expected if the cat was hollowed out..

You can find videos on You-Tube on the knock sensor relocation process