98 Q45 running fine but has trouble codes (new infiniti owner)

[jasonG79]

Hi there,

I'm a new Inifiti owner and new to the forum, and I was looking for some help.

I just purchased a 98 Q45 a few days ago. The car has 174K on it but was well taken care of and serviced by the dealer all its life, it runs smooth and is probably the quietest and smoothest running car I have ever owned.

Yesterday while driving home from work the ses light came on so I pulled over and gave everything a quick check, found nothing. When I started it back up, the idle was wandering up and down for a bit so I shut it off again and started it back up. Idle was fine after that but the light was still there. It drove the rest of the way home like nothing was wrong.

Today I took the car to Autozone to get the codes read and the guy gave me 6 different codes, Infiniti codes: P0125 came up once and P1705 came up twice. There were also Domestic codes: P0330, P0325, P0120. P0125 is something to do with the coolant temp being insufficient, P1705 is the throttle position sensor, P0330 and P0325 are knock sensors, and P0120 is the throttle position sensor again.

The car is running fine though so what gives? The only thing that I have noticed is the idle is a bit lower then when I first bought the car, just above 500 rpm when in gear (not sure what it should be).

Should I just replace the TPS sensor and hope that fixes the other problems?

ThanksJason

[qship96]

Sounds expensive!!!!! Just a small part of the $3,000 always needed right after purchase of an old Q to return to good operating condition.

[bullittandy]

Sounds expensive!!!!! Just a small part of the $3,000 always needed right after purchase of an old Q to return to good operating condition.

Ignore this guy, he knows a lot but is being a jerk.

Knock sensors are a common failure, I would start by replacing them and clearing the codes and seeing what happens.

report back after you've replaced the K/S.

[qship96]

Just speaking the well known, proven truth.....some owners dont need sugarcoating of facts????

[paranoidjack]

These cars (even when hurting - as yours most definitely is) still feel smoother than most on the road.

Those are valid and typical issues at 175k. They need to be addressed before they create other issues (fouling o2 sensors, ruining catalytic converters).

Fortunately for you, there is a plethora of information on this forum pertaining to those exact subjects. I myself wrote a walkthrough on this forum to help other 98-01 Q45 owners with their KS replacement (search for "plenum" and my name).

I hope you plan to keep it and fix the issues.