mrxr250rider

well my cars been driving my nuts. my cel light came on recently code P0174,its been coming on for a couple days going out then coming back on again

ive replaced my plugs,wires,coils,injectors,fuel filter, ran fuel injector cleaner and nothing helped.
cleaned my maf and airfilter as well.

it runs rough past 2k rpms has vibration and low on power.
my cats are ruined from it running lean.

should i just take it to a mechanic? my dad doesnt seem to know whats wrong and i keep throwing money at it. he checked all the vacuum lines and said everything seems fine.
i cant hear or see anything out of the ordinary.

hiboostwoody

I assume this is on the car in your signature, correct? Assuming that:

Code P0174 indicates that bank 2 (passenger side) fuel adaptive system is at the rich correction limit. Possible causes for this are:

Air leaks after the MAF sensor mounting location
Air leaks in the Air Induction system (e.g., in the intake manifold)
Air leaks in the exhaust manifold and it the exhaust pipes
Engine oil dip stick not seated (Wouldn't THAT suck after throwing all that money at it)
Fuel injector(s) restricted or not supplying enough fuel
Fuel rail pressure sensor is out-of-calibration or skewed)
Fuel system not supplying enough fuel during high fuel demand conditions (e.g., the fuel pump may not be supplying enough fuel)
HO2S (oxygen sensor) has failed (it may be contaminated with fuel, silicon or water)
MAF sensor deteriorated or dirty (causes the PCM to underestimate airflow)
Vacuum hose disconnected to the EGR system module on models with ESM
Vehicle running out of fuel or run very low on fuel


You have a lot of aftermarket intake components on that car. Very possible you have a problem with one of them. There are ways to test these components but you need some specialized equipment for some of them. My suggestion is to take it to a mechanic that you trust has a GOOD scanner.

mrxr250rider

i thought p0174 was lean? yes its the car in my sig.

it ran fine after all the mods.
i changed the intake manifold,plenum and tb in the spring.

its ran strong untill say a month ago when i got this problem when having some W0T fun.
then i felt the vibration and loss of power and knew something wasnt right.

thanks for the help.

if anyone can pin point the problem by my decription that would be amazing.
ill probably have to take it to a shop.

hiboostwoody

Yes, it is lean. What the code means is that the computer is reading that it's lean so it is compensating by going rich. That is why the cats are damaged (if they are in fact damaged). The excess fuel burns them out. Without having the car to do some diag stuff on it, I couldn't tell you exactly what it is. The closest I can do is what I posted above although you can probably eliminate the fuel injectors because you have replaced them. If you have can come up with a fuel pressure tester, you can test the fuel pressure and confirm whether or not the pump is working properly. If you have the original MAF, you might try putting it on and see what happens. You can usually find air leaks in the intake system by spraying carb cleaner or starting fluid (I prefer the starting fluid) around the intake mounting surfaces and the air intake after the MAF while the car is ideling. If you get a change in RPM, you have an air leak in the area you just sprayed.

mrxr250rider

thanks. i tried spraying maf cleaner around seals on the cai tb,plenum and some vac lines.
didnt hear a chance in rpm but that was with maf cleaner idk if that will work the same.

1956_4x4

Ok, I'm going to ask a dumb question concerning these possible problems. Most of this list of problems should impact both bank 1 and bank 2. Is it possible for the computer to set a code for only one bank if the problem impacts both banks? Just about everything on the list that I'm looking at should set a code for both banks, unless I'm missing something...

Smitty

hiboostwoody

MAF, EGR, and fuel pump problems might cause problems with both banks but not always. It depends entirely on the demand placed on the fuel system as the O2 sensors read it. If the intake is leaking on only one side then only that side will be lean. Same with a bad injector.

Also, everything I posted came directly from AlldataPro and Indentifix. I use these two programs at work to chase down tough diags. They are rarely ever wrong.