Kayloe

Hello everyone!
This is my first post on these forums, and I'm looking for a little guidance.

1996 Grand Am SE 2D
3.1L 6 Cylinder
130,000 Miles
The acceleration is very horrible (Takes almost 19 seconds to go 0-60). Gas Mileage is also horrible, averaging 190 miles per tank.

Heres my OBDII Codes
P0102-Mass Air Flow (MAF) Circuit Low Input
P0141-02 SENSOR HEATER CIRCUIT MALFUNCTION (BANK 1 SENSOR 2)
P0300-RANDOM/MULTIPLE CYLINDER MISFIRE DETECTED
P0401-EXHAUST GAS RECIRCULATION FLOW INSUFFICIENT

So, this is what I've done in the past ~4 months:
Replaced spark plugs and wires
Replaced air filter
Replaced fuel filter
Replaced the after-cat O2 sensor
Replaced the Fuel Pressure Regulator (FPR)
Replaced the Exhaust Gas Recirculation Valve (EGR)
Repaired a vacuum leak along my PCV valve line
Treated the gas tank, crankcase, and vacuum line with Seafoam
Changed the oil
Changed the transmission fluid and filter
Cleaned the MAF and Throttle Intake
Replaced the catalytic converter
I have thoroughly inspected for vacuum leaks, and there are none currently present...

Problem still persists... what now?

I Love (.)(.)

does it have coil packs?

Fabrik8

Welcome.

You obviously still have the same problems you had before, even after replacing all those parts. That tells me two things:

1: You're not troubleshooting, you're randomly replacing parts.

2: Randomly replacing parts is not working, and you need to do some troubleshooting.

Sounds obvious, enough, right?



So you have a MAF problem. You've cleaned the MAF. You still have a MAF problem.

One of these things (probably) applies:

• You need a new MAF
• You have a wiring problem,
• ECU is bad

I don't know if your car has a digital output Delphi MAF or not (many GM cars do) and if you do that's probably beyond what you have the ability to properly test. You could check that the sensor is getting enough voltage though, as that can be done without starting the engine. If you have a Delphi MAF, the ECU is getting a digital signal so it would stand to reason that the only way the ECU would report some type of "MAF low" fault is if the sensor itself is bad and isn't measuring accurately.



You have an O2 sensor problem. You've replaced one of the O2 sensors. You still have an O2 sensor problem.

One of these things (probably) applies:

• You haven't replaced the correct O2 sensor
• You have a wiring problem
• The O2 sensor heater isn't getting power
• ECU is bad

O2 sensors usually get power from the battery (through a fuse and/or relay of course) and the ECU switches the other side of the heater element to ground, completing the circuit. You can check if there is power getting to the heater element. You can also check that the ECU is switching the other side to ground. If either of those checks fails, you can check the continuity of the wiring.



You have an EGR problem. You've replaced the EGR valve. You still have an EGR problem.

One of these things (probably) applies:

• EGR port is plugged where the tubing meets the intake manifold
• EGR ports is plugged at the other end of the tubing
• Differential pressure sensor monitoring the EGR is bad
• Differential pressure sensor wiring is bad
• Actuator solenoid controlling the EGR is bad
• Actuator solenoid wiring problem
• ECU is bad

My hunch is that you have a clogged/gummed port, which is probably also causing the misfire problem.
An actuator problem might also cause the same symptoms (I know practically nothing about that engine so I can't say), but check the EGR ports first.

You have to disassemble stuff to check the ports. Pain in the ass, but it's free and a very likely cause of the problem. You can check the continuity of the diff. pressure sensor wiring. You might be able to test the diff pressure sensor voltage output, I don't know much about GM's sensor though. To test the actuator solenoid I think you'll need a vacuum gauge, I don't remember.


Disclaimer: I don't really know anything about that particular car, so I can't help very much with where to check stuff or the exact specifics of troubleshooting.


So, do you see how many things can be checked without replacing parts blindly and randomly? You should replace parts because you have found them to be bad, not just because it might be the problem maybe.

You could replace the entire O2 sensor system, and the problem could be a blown fuse. You could replace the entire EGR system, and the problem could be a clogged port. Replacing parts randomly might never solve the actual problem.

Lord Humongous

^what he said

Kayloe

To the last poster... I have only blindly placed a few parts.. so let me break it down.

Replaced spark plugs and wires (Bought this car in October, last owner did NO maintenance other than changing the oil, this is part of necessary maintenance. The car came with no records.)
Replaced air filter (Bought this car in October, last owner did NO maintenance other than changing the oil, this is part of necessary maintenance. The car came with no records.)
Replaced fuel filter (Bought this car in October, last owner did NO maintenance other than changing the oil, this is part of necessary maintenance. The car came with no records.)
Replaced the after-cat O2 sensor (Had a code for this specific O2 sensor a few months ago, likely due to the condition of the old cat converter. That code went away)
Replaced the Fuel Pressure Regulator (FPR) (Was leaking gas)
Replaced the Exhaust Gas Recirculation Valve (EGR) (Blind Replacement due to trouble code)
Repaired a vacuum leak along my PCV valve line (Was a vacuum leak, enough said. This fixed the very rough idle/stalling problem I had)
Treated the gas tank, crankcase, and vacuum line with Seafoam (Bought this car in October, last owner did NO maintenance other than changing the oil, this is part of necessary maintenance. The car came with no records.)
Changed the oil (Bought this car in October, last owner did NO maintenance other than changing the oil, this is part of necessary maintenance. The car came with no records.)
Changed the transmission fluid and filter (Bought this car in October, last owner did NO maintenance other than changing the oil, this is part of necessary maintenance. The car came with no records.)
Cleaned the MAF and Throttle Intake (Bought this car in October, last owner did NO maintenance other than changing the oil, this is part of necessary maintenance. The car came with no records.)
Replaced the catalytic converter (Old one was rusting out, and will soon need to replace the muffler)

Your reply was helpful, but very rude. Sorry I am just trying to ask for some help here...

Fabrik8

When you say "I'm having these problems, and this is the massive list of things I've replaced in the last 4 months... ...problem still persists", that sounds like you've been blindly replacing things trying to solve the problem(s).

So almost everything on the list was done for reasons other than the problems you're currently having, so you really haven't done much to try to solve the problem (if I'm understanding correctly according to the last explanation) except clean the MAF and replace the EGR valve. The problem still persists, but apparently you haven't been doing much of anything to try and solve it..?

I'm not being rude, I'm just being jaded and tired of people who don't try to find out what the problem is before throwing money and new parts at the problem. You're not one of those people apparently, so don't take it to heart. I know you're new here, so what I'm saying probably doesn't make any sense because you haven't seen it yet. Stick around and you'll see what I mean, trust me.

This is also your test to see how you deal with people on this forum. I'm one of the really nice helpful ones.

drunkard

Maybe get a new car?

junction

+1

I Love (.)(.)

fabrik8 wasnt being rude imo at all. infact that was one of the most informative things someone could have posted actually. he broke down the possiblities it could be. things you obviously havent tried to trouble shoot. take his advice and run with it. hes one of the most helping people in this forum. +rep for you fabrik8 when i can

stinks

^^^ i tried but i have to spread it b4 i can