ariethekid

I have a 2000 Integra Type R and I have a pesky code that keeps popping up. P0170 and P0172 for fuel trim malfunction and I have no idea what it is.

Things I've done so far:

Changed O2 sensor
Checked Fuel Pressure, ~45 psi, seems good.

The trims hover around -25% and go to 0% in WOT. It is running very rich. I can see smoke out the back. And the code comes on after driving about 30-40 miles.

The car does have a no name exhaust header and a comptech cold air intake.
Could that be causing the problem? I also suspect an exhaust leak because I can smell exhaust in the cabin sometimes. There is also no catalytic converter on the car. Could any of these be a culprit?

This is my first integra. I've had a couple of civics and an RSX. Never seen a rich code before. I've seen cars run lean before more often but i'm lost. any help would be great.

B16EJ

I think you might have a vacuum leak of some sort, I had the same codes in my 99 itr after I changed a bad map sensor.

It turned out that the O ring supplied with the map sensor (aftermarket) wasn't a perfect fit and that Lil leak threw both of those codes. I put the OEM o ring in and that fixed it. Good luck

VegaS10

Which O2 sensor did you change?

ariethekid

I'll have to see about this map sensor seal. I'm getting 4.6 psi intake manifold pressure. Or -10 psi depending on what you're used to. It's na, not boosted.

I've changed the primary o2 sensor.

At this point I'm thinking, a vacuum leak or a leaky injector.

DC2-ProdUcTiOnS

iTrader: (2)

I just got this code as well. I think mine is from my 310 injectors with the USDM ECU though. I have a FPR and a 255 in the tank, so i think that is whats pushin it so much.

My psi gauge on the fuel filter reads about 55psi at idle which i think is dumping too much as well. Im going to dial it down a little and see if that helps it out.

Is 45psi the range it should be at idle??

ariethekid

My manual says 40-47 at idle. So 45 is probably fine.

DC2-ProdUcTiOnS

iTrader: (2)

and under load what should it spike to? Any idea?

B16EJ

Dam it the codes came back on my 99 R, I can't seem to figure out why I'm throwing these codes... So frustrating!!

DC2-ProdUcTiOnS

iTrader: (2)

seems it should be in the same range under load.

Looks like im turning mine down!! lol

Do you have a walboro pump in yours??

Do you have a FPR? If so you might need to modify your FPR to allow better circulation it seems.


Here is what I found.

http://theoldone.com/articles/regulator/

ariethekid

Mine still stays between 40-50 under load. it doesn't really go over 50 though. I'm not sure if the fuel pump is stock but if it isn't, that would explain a lot. The owner before me had a turbo in the car for a short while but took it out after it he sold it to me. He might not have put the original pump back in. I'll have to check that one. Other than that, everything else under the hood looks stock. I might snag a MAP sensor from the junk yard and some injectors just to see if its that helps.

First things first the pump, then all that other mess. I don't have an adjustable fuel pressure regulator but that article that was posted looks interesting although I don't think it would be necessary since the fuel pressure was within spec for me. I have a feeling its the MAP sensor or a leaking injector in my case though.

ariethekid

What do you have done to your car? Is it stock?

B16EJ

I had the motor and trans completely rebuilt last fall and parked it after the rebuild, I just got it running and changed some last few things, the map sensor, distributor and plugs.

It is also stuttering and sputerring when I accelerate, it happens in every gear, so there is a very obvious problem I just fit have the time to spend playing around with it to find out what's wrong. I apologize for thread jacking but I'm hoping that since we have similar cars and the same codes that it will be the same issue.

ariethekid

So I decided to try pinching the input fuel line today about half way and that seemed to make a difference. The Map sensor values seemed to be ok. I'm going to change it anyway though because it doesn't have a sticker or anything on it so I don't trust where it came from.

Fuel pump may be a walbro or something because when i pinched the fuel line a little bit the trim went down closer to 0% where it should be.

So injectors, map, and a fuel pump sounds like it would definitely fix my problem. If not that, then an FPR.

I'll change out those things tomorrow and let you guys know what changes.

ariethekid

FIXED!!!

Replaced injectors...

Took them out of a 96 Acura RL in the junk yard. Trim sits right where its supposed to at idle now. Before it was -20 to -30 % now its at 0.0%.

Also replaced the Map sensor out of a 97 Accord. Car runs like a champ now.

B16EJ

I will try the injectors next and see what happens... I changed the map sensor already.

B16EJ

Well, 440 km's of driving and the head gasket blew lol. Fresh rebuild and now the motors full of coolant, I'm tearing down the head as I type this, and my buddy who is a Honda technician is going to install a new head gasket and intake gasket.

Hopefully this time it runs for a bit longer...

b18a1crxsi

I have been chasing these same two codes in my 00 prelude for almost two years now. I have done almost everything beside replace the fuel injectors. I replaced (2) 02 sensors, (2) diffrent fpr one new one used. Checked vacuum. Cleaned egr ports and egr. Installed a pressure gauge on the fuel rail and all the pressures r in spec. I have tested all the voltage at the map sensor. Tested every vacuum solenoid and they all held vacuum and released it when I powered them. Cleaned ive changed the timing belt like 3 or 4 time becuse of everything breaking, like the seal, then the crank sensor, then the water pump leaked, then cam seal blew, im sick of working on this thing. Just got done changing intake manifold gasket becuse it was leaking and i thought that the intake manifold gasket and plenum gaskets would fix it but no.
It runs prefect while your driving down the road. When it's idling the stft is -25 to -19 and when u rev it up just past 1000 rpm the trim go's perfect to -6 to +6. But i once tried to pinch the inlet fuel line and the fuel trim went back to normal but wasn't shure cuz the pressure was in spec and it held fuel pressure for like 3 or 4 hours after i would shut the car off.

But after u say the injectors fixed your problems im going to buy some. I just need the check engine light out to get a inspection sticker. Ive read i think every thred on honda and code p0172 and u where the only one who replied with a FIX!! Thanks. Sick of being mad at my Honda, i love driving this car

ariethekid

Good luck. There's a good chance that will fix your problem. If its just running rich at idle you might just have a leaky injector. I pinched off the line and that seamed to improve the numbers. All the other numbers looked ok with mine as well. Post an update if you get it figured out. That was such a headache for me. Lol.

b18a1crxsi

Yea I definitely will. Maybe it will help the next guy down the road. Oh I forgot, i also gutted the cat cut I thought all the fuel eaten it up and maybe melted. When i took it out it looked really good for having around 270k miles. It was melted about the size of a half dollar in the middle of the engine side. The honny come was not plugged u see through it. It was probably fine but i drove a pry bar through it and that took care of that. But it didn't change the way ran, still rich *** ****. It almost steams unburnt gas out the muffler its dumping that much gas only at idle thow. The check engine like will not come on if u dont let it idle. Like u stop at a light and as soon as the idle go's to 700 or so the stft graph go's slowly rite to -25 then bounces to -17 and back. If I manually keep the rpm at 1200 or above it go's normal. Ill try the injectors i can get brand new ones through my work for around 62 bucks so not too bad.