ray6712

Yo IHC great post brother however I do know of a few things that can cause both banks to run lean some you probably would never suspect. A bad or cracked pcv valve or leaking hose, a leaking power booster seen it with my own eyes, and yes a leaking intake in the right spot can and will make you lose enough volume across both banks to set these codes its crazy but Ive seen it.

vtec22

yes, i cleared the code changed and one O2 Sensor. I have no other complaints ;-)

I hate cars

An air leak can cause a MAF car to go lean. But on these crappy speed density Hondas it would just raise the idle. The exception would be a single cylinder leak at an IM runner or intake to head.

robocam

Which O2 sensor did you change? Did the codes ever come back? My 06 just threw a P0174 today. I cleared it, and I'm going to run through this tank of gas before I do anything else. Are the O2 sensors easy to access and replace for a DIYer?

BxTrini_TL

My 04 MT threw po174 then came off... couple days later both po174 and po171 came on.. waiting on the snow to stop and will check for vacume leaks. A Azine member Vlad_Type_S pointed out a software update. If its the o2 sensor, which one is it? How many o2 sensors does our cars have?

Louboogie

I got both of these codes and they keep leaving and popping up at random times...any found the fix yet??

mang03

Hey whats up I know this is an old thread but I got 3 codes p0401, p0174, and p0171 at the same time!
I have cleaned the erg twice now and i have done the seafoam treatments besides the oil part and every other tank( for the month) of gas I put seafoam
now the codes keep going away on their own and then like two days later they come back but last night I pulled the codes and I only got the p0401 does this mean I have to buy a new erg valve since I didnt get the two other codes? Thanks for any info

mang03

Oh also the car runs fine the idle is steady and yet the code comes and goes as it pleases. Any two cents will help

Timstandupguy

i wrote on this like last year. all those solutions to that problems i tryed i got the map sensor change out bank 1 and i also go an pgm update. but what solved my problem was an valve adjustment the valves were a tap bit loose that was enough to release the emission a bit then cause the other codes to trip. i did that at 57k now am at 90k and no check engine light hit. i wanted to refuse to believe that the valve adjustment was needed because i thought the dealer was trying to jerk me but. i had a few ppl with the same car that told me that its the valves fellas get that check out. your gas mileage will improve slightly.

other problems i had was that tighten gas cap fix that the dealer replace it with a new pcv valve. the other one was made in mexico so it was defective the new part was japanese made so you know that went will

then that map senosr i replace when that p0171 show up
valve adjustment and pgm update

mang03

Hey timstandupguy how much was the valve adjustment? Also whats a pgm update for or what I mean to say is whats pgm?

I hate cars

I tried to follow but I literally can't make sense of this post. I'm not the grammar police but a little effort to make it readable would be appreciated.

mang03

Hey ihc what do you suggest?

nfnsquared

Very hard for me to believe that a valve adjustment fixed Timstandupguy's issue, especially with only 57K on the engine. It's certainly possible, but I really doubt it.

And the same thing for Mang03. Unless you have a ton of miles on the engine, I really doubt a valve adjustment will do anything for you.

mang03

Well I do have 124,000 miles for an 07 tl-s auto

nfnsquared

I hate cars

I have to agree... And if I read that last part right, he replaced the PCV valve to get rid of the "tighten gas cap" light???

mang03

Ok if I take the intake off and clean the ports shown in the video do I need a gasket
And do I need to torque the intake back on? Sorry guys for all the question and thanks

nfnsquared

Gasket: No, you shouldn't (disclaimer: the SM says to replace the gasket, but I didn't and it's fine).

Torque: You should, and there's a specific order listed in the SM. Do a search for the online SM link . Better yet, spend $50 and buy a SM. Well worth the money if you are going to continue maintaining the car yourself.

thoiboi

IHC, he isn't completely crazy, but he definitely needs to proofread his posts, it's really hard to read.

https://acurazine.com/forums/3g-tl-problems-fixes-114/check-fuel-cap-message-nav-well-mid-784101/

PCV issue causes the "Check Gas Cap" light to come on

Vlad_Type_S

iTrader: (3)

I got the P0171 and P0174 at the same time. PCM update. Both codes went away. I got a P0171 several weeks later. Cleared it and it came back. Took to dealer under warranty. They said I needed a valve adjustment and wanted me to fork over $600 bones even though I bought a warranty from them. I took it home, did the valve adjustment (nothing else, no parts replaced or cleaned or anything like that). Code never came back.

The repair manual specifies that performing a valve adjustment could resolve a P0171 or P0174 code, too.

I know most of you guys are saying that it's very unlikely, but now there are two good examples (plus the service manual) that show a valve adjustment could be the resolution to this problem.

nfnsquared

You didn't clean the manifold at all? Man, that was a major mistake IMO, just saying.

Glad you got it resolved though

Timstandupguy

i got the Adjustment for 300 bucks flat. at 57k yes i did need the adjustment i try every step there was to delete that code p0171. the Acura Repair guide stated that the Valve adjustment is the last step to resolved my issue and it did work and at 90k im still free of that code and have no noticeable problems.

nfnsquared

Glad it's working, but you don't really know that it was the valve adjustment that fixed it. It could have been a simple cleaning of the manifold....

I hate cars

I see, "purge control valve". I wouldn't use the PCV abbreviation since it's meant "positive crankcase ventilation" for 50 years. But yeah, not as crazy as he sounded at first. By saying "PCV valve" he's saying "Purge Control Valve Valve" which is why I was thinking positive crank case ventilation valve.

YeuEmMaiMai

you know you can buy a Launch Creader V for under $50 and it will go a LONG ways towards helping you diagnose problems via live data streaming. You plug that baby in and then take a look at the values that it is reading out for [insert sensor here]

that way you can look at the MAF readings and O2 sensors (all of them) and get an idea of what is up.

Vlad_Type_S

iTrader: (3)

Haha yes this is very true, that was a mistake, but I wasn't able to do anything about it anyway because I was too crunched for time and was using someone else's garage space.

However, my mistake in not cleaning it is a pretty good case study that the valve adjustment could resolve this DTC, since the valve adjustment is the only thing that was done and caused the code to disappear.

nfnsquared

It's certainly possible. How many of your valves were out of spec and how far was each out of spec?

Vlad_Type_S

iTrader: (3)

I was not smart enough to collect that data. But I recall almost all of them were out of spec. Some much worse than others, but I definitely adjusted each one. Not surprising considering the car had been running a regular conventional oil at a 5k/6k interval up to that point.