Running Rough

MacKiNBacK · #1 (**permalink**) 04-26-07, 06:05 PM

I wrote a thread a little way back about P0171 and P0174 codes.. Lean bank's 1 and 2. I believe it was Ranger who said it might be the FPR going bad. Well I talked to Goodyear (we go there very often with family cars) and the tech told me if it's lean bank its more than likely not going to be the FPR, but the mass air flow sensor. Does this sound some what accurate? I also got a P0300 missfire code and its runs pretty rough. Though I do notice the car is a little more peppy when the service engine light is on. Mostly due to the lean banks and the engine putting more gas in no? But anyways the car is going in tomorrow mainly for the warped rotors I have and they are going to look at it. Just dont want to be screwed over. He quoted me at $80 for the FPR if I want it replaced and a 1/2 hour install. I know it takes like 5 mins to take it out so who knows what they would say about the mass air flow sensors..

Thanks,
MacK

misfit6794 · #2 (**permalink**) 04-26-07, 06:14 PM

Mechanics are out to screw you, even if you consider them your friends. A fuel pressure regulator may be the easiest thing to change next to an air filter. Ill gladly install it for 40 bucks, ha. THeres a write up with pictures in the tech tips section that shows you step by step how to do it. Did you pull the tube off the top of the fpr to see if its bad? Mass air flow sensors can cause the car to run lean. They aren't cheap, and you definetly shouldn't pay someone to put it in. They are the next easiest thing to change, after the fpr. If both those things check out, id look at your o2 sensors, since you have a check engine light. O2 sensors will most definetly cause your car to run lean or extremely rich. Good luck, and dont be intimadated by the northstar, its alot easier to work on than you think.

**Ranger** · #3 (**permalink**) 04-26-07, 06:27 PM

Wasn't me. A leaky FPR would cause a rich condition, not a lean one. I'd look for a vacuum leak for both banks lean.

Krashed989 · #4 (**permalink**) 04-26-07, 07:09 PM

I would hook up a fuel pressure gauge to it.

**Playdrv4me** · #5 (**permalink**) 04-26-07, 07:27 PM

A MAF Sensor is so easy to change. Do not pay anyone to do this.

MacKiNBacK · #6 (**permalink**) 04-26-07, 10:21 PM

I do recall hearing almost a hissing sound when the light was on. Kind of narrowed it down to the throttle body area but not sure what else to do. Yea I wouldnt have them install anything either.. That's what I got the service manuals for and have yet to use them. hah.

MacK

lbwd · #7 (**permalink**) 04-26-07, 10:47 PM

Got my FPR for $65 at the dealership. My friend installed it for me and it was fast and easy.
Can't the mechanics hook it up to their hardware and tell you what the problem is? That's what they do here. Their stuff will show more than the OBD II.

If you install it yourself, also remove the gas cap before the install (to let any pressure out).
I don't have many ideas as to why it runs rough. Are all your ignition coils in good shape?

**Ranger** · #8 (**permalink**) 04-26-07, 11:38 PM

Removing the gas cap will not relieve fuel pressure. You have to either bleed it off at the service port or pull the injector fuse or ICM connector and crank the engine.

MacKiNBacK · #9 (**permalink**) 04-27-07, 12:04 AM

Last time I had the FPR out I used the service port.

MacK

MacKiNBacK · #10 (**permalink**) 04-27-07, 04:07 PM

Well goodyear said theres a vacuum leak on a rubber hose inbetween the throttle body and the intake manifold.. Quoted at $450.. Lol.. Hold them to hold off for now until I figure out if I can do it or not. Hmmm

MacK

chubbyranger · #11 (**permalink**) 04-28-07, 01:30 PM

$450 to fix a hose?!? I knew college was a waste of time.

raymondk · #12 (**permalink**) 04-28-07, 05:10 PM

Check the coils first it's the easiest to do. Each coil fires 2 cylinders. Pull each wire and check for 5-20K ohms on the wires. then check across the two output post. I forget something like 3-50 ohms or so mainly they should be the same. Misfiring causes raw fuel in the exhaust making it look rich, and the ignition high tension section is the only major system not monitored by the ECS. Mine cut up for over a year before finally missing consistently.

MacKiNBacK · #13 (**permalink**) 05-07-07, 12:45 PM

Well me and my buddy took a look at the vacuum leak.. And we're pretty sure its the seal between the manifold and throttle body. Checked all lines and they all seem ok. So we're looking at taking off the throttle body and manifold to get to the seal.. Now my question is.. Does anyone know the part # for the seal for manifold to throttle body? Also does the manifold to block not have a gasket?

Thanks,
MacK

**Ranger** · #14 (**permalink**) 05-07-07, 12:49 PM

Certainly there is a gasket sealing the manifold to the block, but are you sure you need to remove the manifold and not just the TB?

MacKiNBacK · #15 (**permalink**) 05-07-07, 01:19 PM

Reason the manifold needs to come off is because we're trying to avoid removing the water crossover and the gasket is between the water crossover and manifold. And theres a bracket between the crossover and throttle body with bolts that are covered by the TB. Sorry I just opened my service manual to get the names right. So it goes manifold - gasket (bad) - bracket - watercrossover - TB. Also the reason why im not sure there is a gasket for manifold is under manifold replacement in service manual they dont say anything about a gasket. The actual name of the seal that is bad is rubber plenum duct (dont know a part #).

MacK