Q45 running weird...Please Help!!

[RockSteadyQ45]

So here's my story...got a 97 q45 back in june for 800 with 116k on the dash. I got it so cheap caus it has some font end damage and is missing a grille..Pretty good deal I thought. Now back in late july early aug she starts loosing acceleration going around corners and up hills. Also some times when going down a straight stretch on the highway. It always starts with the Rpm going between 1000 and 2000 sometimes close to 3000 but then drops down after a few moments and me removing my foot from the gas peddle a few times. Oh also sometimes when I start the car I can smell a lot of gas fumes that go away if I let it run for about 30sec. I've heard a lot about knock sensors and 02 sensors and (hopefully not) but also a fuel pump, but I'm not sure where to start. I picked up some new spark plugs by have yet to put them in cause I'm not sure if their the right ones. They are ngk g power I wasn't sure if I needed the laser series or not. I would post a picture of my baby when I get a chance by any help now will be most helpful. Thanks in advance.

[Q451990]

to NICO!

With all of this, I assume you have a "check engine" light illuminated on your dash? If not, make sure it lights up during the gauge self test when you first turn the key on. If you can get us the code(s) stored in your ECU it will help.

Failing coil packs are very common on the 97-01 Q45. Your issue sounds a lot like a failing mass air flow sensor on the older Q45s, but that's rare on your series... maybe it was damaged in the front end collision? I would also check for fuel pressure problems. I would use only the correct OEM NGK Platinum plug for your Q. It should be listed in your owner's manual, available at www.infinititechinfo.com under publications. You can also view your FSM (factory service manual) at www.nicoclub.com/FSM/ - I think the '97 copy is incomplete, but the '98 model was very similar and should work.

Heath

[loystock]

Welcome to NICO,

Your best bet is to have a free OBD II scan from Autozone and the likes. With the kind of problem you are having, most likely you have multiple problems - catalytic converter efficiency (P0420/0430), Knock Sensor (P0325) and misfire (P030x). The recommended plug is NGK PFR5G-11. Check the current plugs in the engine. If they are Bosch, replace them immediately as they could damage your engine.

[RockSteadyQ45]

Oh yes I forgot to mention the check engine light..yes it did turn on I had one for a knock sensor, and also for an o2 sensor. Althou a few weeks back I removed the ground wire from the batt and the light went off and had the codes re read and nothing about the o2 sensor came up...then about 3 weeks later the light came back on and is still on now. I haven't had it read since it came back on. I do remember the o2 code said something about too rich or too lean air mixture. The plugs I have are platinum just not the laser serise. I eventually plan to check all these things I just need a place to start and I don't have 90-300 bucks for to have a shop in my aera "take a look at it" (their most commonly used phrase in CT ).

[loystock]

After resetting an O2 sensor fault, it may take a while for the fault code to come back, unless there is an open/short circuit. A faulty Knock Sensor will not turn on the CEL but your acceleration will be lousy due to ignition timing retard. A faulty O2 sensor may result to richer than normal air-fuel mixture, which over time, may eventually impair the other O2 sensors as well as possible damage to catalytic converter. An NGK/NTK O2 sensor, depending on the location, cost $60-100. The OEM Bosch is usually over $100. In most cases, you need an O2 Sensor adapter (@ $10) when replacing the sensor to prevent damage to the harness.

It's never a good idea to ignore the CEL as it could lead to more complicated and expensive repair.

[RockSteadyQ45]

OK so ur saying I should return the plugs and worry about the supposed o2 sensor?

[elwesso]

KS problems on the later Qs seem to have a lot more affect than on the early ones.. I would lean more toward that being an issue.

On these cars, the fuel trim from the o2 sensors is not that much.. It also depends on what o2 sensor is throwing a code, if its a rear o2 sensor (sometimes called sensor 2) you will have no drive ability issues at all.. A front o2 sensor might cause some issues, but I highly doubt it would cause any acceleration issues or start adding enough fuel for you to be able to smell it.