Hello
2004 Mitsubishi lancer ralliart
I keep getting a P0171 system to lean bank 1 and P0136 system bank 1 02 sensor 2
and every now and then it will say there is a random misfire. I do have a ram air in it. I have taken the mass airflow sensor out and cleaned it with mass airflow cleaner as well as all my pipes and made sure everything is good with no leans around anything check my exhaust made sure of no leaks and nothing I have cleared the codes many times and always come back within 20 miles of driving they don't come right back anyone have any ideas please help thank you

 

Clip your purge valve solenoid hose.

It will fix your idle problem also.

 

i still cant find where this hose is i feel so n00b maybe cos i am lol

 

why are we clipping the hose? it's the way it is for a reason...the problem is not that the hose is "not clipped".

for the OP, sounds like you have a failed O2 sensor...

 

You will get a P0171 with the following intakes:

RRM
Anything from ebay.

Replace your o2 sensors.

 

LOL that's so true. it wouldnt be there if it was supposed to be snipped off anyways right?
and im pretty sure that somewhere down the road, clipping that hose will lead to another issue that might be more troublesome/fatal than just rough idling & engine codes. just my 2 centavos.

^^^THIS^^^

for the OP:
THIS--> https://www.evolutionm.net/forums/04...-bank-1-a.html
THIS--> https://www.evolutionm.net/forums/04...0171-help.html
THIS--> https://www.evolutionm.net/forums/04...-too-lean.html

and youll find so much more if you just do your due diligence of searching.

 

the evap purge valve/solenoid is only there to help reduce emissions...
if you "snip the hose" and block it off all you're doing is bacially closing the valve that most likely is stuck open...therefore you're just doing it's job for it...permanently tho instead of temporarily as it's designed to work...

so it's really not going to cause anything else to go wrong over time...except maybe the hose degenerating enough over time from being pinched and causing a lean condition(wich u had to begin with)...

IIRC the evap purge valve/solenoid is designed to open at a cruise so that the engine sucks out, and burns (thru normal combustion) any extra fuel vapors (wich are minimal and won't affect your fuel ratios) from the tank, instead of it just leaking out elsewhere(aka gas cap) directly to atmosphere and comtaminating the air etc, etc....
if the engine rpm isn't high enough, and the valve is stuck open, it'll lean out the system because it has too much air which it sucked in thru the fuel system
because it sucked out the fuel vapors, and when they run too low, it sucks is only air with no vapors, even tho it expects to suck in a certain ammount of vapors and air...
but now there's no vapors...so it throws a lean code instead, and stumbles when the rpm is low...

anybody please correct me if im wrong...
EDIT: here's a link to basically the same info i wrote out...all long and fancy and technical...
http://www.wisegeek.org/what-is-a-charcoal-canister.htm

but w/ that o2 code..it probably needs o2's too...so they may be throwing off the fuel ratios enough to cause a lean condition simulating other issues...
plus they shouldn't be to expensive...and they're easy to replace...(just don't do it when the engine is hot or you could burn yourself on the hot exhaust...and don't forget they're attached to the exhaust so they get hot too...very hot)

 

yeah i read about the purge valve solenoid somewhere on google. but wouldnt that mean that the vapours will go straight into the evap charcoal cannister? wouldnt that mean that the cannister might be overworked? i dont know. im kind of not too shabby at "taking things out of the equation when it doesnt work" as im more of the "it should be working so why is it not" type lol.

it sounds too good to be true that yanking something out will resolve a problem. i guess the only solution (other than block the hose) is to replace the purge valve solenoid itself. hmmm, decisions decisions lol.

i dont want to spend that money on that solenoid so this fix might just work. but the thing is, what if its not the HOSE thats causing the problem. what if theres a leak somewhere that were not finding? you know what i mean? i think thats what Garrett's talking about too.

 

Thx nekkidlad for that well written explanation. I recommend clipping the hose for diagnostic purpuse only, all it takes is a pair of vise grips and a turn of the ignition to figure it out. This has been thouroughly discussed, some forum search might not hurt. If you are unsure about this matter, I'd strongly recommend you take your car to an experienced mechanic.

 

i did take my car to an "experienced mechanic".
what they told me is they have to do a leak test in the EVAP system.
they're going to put coloured smoke inside the fuel tank and test for any leaks, faults, etc.
they never said anything about "clipping/blocking" the purge valve solenoid hose.
i'm just saying that voiding a certain part that was manufactured and shipped with the car shouldnt be the only way to resolve this.
thanks for the advice though!

 

the charcoal canister is there to help contain vapors...actually the fuel vapors go through it before they go to the engine anyway...so it's normal for fuel vapor to be in the canister...it can't really be overworked unless you get liquid fuel in it...
liquid fuel on the other hand, can damage the carbon canister, purge valve and electronics in/on/near the canister and purge valve...and is most ussually caused by overfilling your fuel tank...
just one reason why it's not advised to keep clicking the fuel pump handle untill it's "all the way filled"...not to mention you may leak fuel all over the place(wich is the main reason you shouldn't)

ps the smoke testing is just a way of finding possible leaks in the evap system to atmosphere...tests for an external leak...

question: but what if you have an internal leak(wich doesn't leak out to atmosphere..), like when the valve is stuck in the open position..?
answer: then u close it manually(aka pinch the hose) and u test if it fixes the issue...
if it does, u found the problem fix and retest...
if it doesn't, something else is wrong, keep looking

 

how much is the purge solenoid? you can do what xmaster is saying (as he said for troubleshooting), but if that straightens it out, you'll want to replace the solenoid...

 

wow.
i learn so much everyday.
you guys are the bomb!
thanks guys for all the input.
i love this forum!
it's like MECHANIC school on STEROIDS lmfao!

 

If the part that the car was manufactured with is causing more harm then good, then no it don't.

 

it's not your insight that's unwelcome, it's your attitude...every time someone doesn't take what you say as gospel, you get all pissy...this is a forum, it's for discussion. people are more than welcome to disagree with you, even if they are wrong (or you merely believe they are wrong). If you know you are right, you can offer theory or evidence as to why you are correct, and if the person you're trying to help doesn't take your advice, leave it at that instead of coming back with douchy comments like the one i'm quoting. Engaging in a civilized discussion or debate is obviously reserved for the mature, if you don't like it, GTFO.