I can clean it (would like to), but I'm still fairly stumped at the fact that it drives so good. The one complaint is like what the guy above said about a "rat jumping on the throttle 'cable'". It 20-25mph, cruising in 3rd, the throttle can kinda bounce. I always wondered if it was just my foot bouncing on the gas pedal and then the bouncing causing my foot to bounce more, but it is a bit odd. Other than that, power is great, fuel economy is ok. Once this is fixed I hope to get much better mileage.

I'm kinda lost, what do we have left to check? What's up with the "diode hack"? Where would that be done if it was the case? I still feel like there could be a small modification somewhere. Since the previous owner (two owners ago) did "such a nice job" on the air filter and loud catback exhaust, I figured he may have done something else kinda sketchy.

I started a thread on the Ericthecarguy forums. One suggestion is to check if it holds fuel pressure or is MAYBE all 4 injectors leak slightly?

I need to get my 5 gas analyzer working... I've never used it. Would it work right if I plugged it in post cat?

 

Idle Up Electrical Load diode transmits signal one way to the ECU when headlights or rear defroster are turned on (when this signal is detected by ECU it increases idle up.
When someone clips this signal wire and jumps the ecu terminal to 12V source, the ECU will increase the idle. But I don't think it will change the a/f mixture ratio though

 

Ok, just curious. Interesting hack.

So where do we look next then? Back to square one?

 

I was able to get an O2 sensor from an 07 accord and it obviously wasn't compatible. I got an 1157 code.

 

Here is a picture of one of my injectors. Looks stock to me, but I wanted to confirm...

 

Same as mine.
It may be silly, but I would definitely try to find air cleaner cover with stock type air filter

 

I did just pick up a used EGR valve. It should arrive in the mail sometime soon. Just because mine was positioned funny I figured I would give it a shot. After that I will look into getting a stock air filter setup.

 

Well, I replaced the egr and it made no change.

So, I've ran the car with no filter on it and it doesn't change the fuel trims. At what point should I look at the ecu? I just feel like I'm running short on options.

-30 for fuel trims is pretty significant. Im trying to think about what else could possible cause that.

 

What was your idle after air filter removed?
I never explored this option on late models OBD2 cars but would reinstalling original software on ECU be more cost effective than swapping it?

 

So today it would not idle, I got it to the shop and it had a 355 Crankshaft position sensor code. Then later in the day it went away. Idles ok now. Could these be related?

Maybe an ecu issue?


I also have an intermittent window switch problem... oye...

 

I would look on the sensor connector or cracked case of the sensor.

 

Ok so-

P0335- I noticed that I have oil on the front of my engine. Looks like front main seal. So that is probably my 335 issue.

I also took my car to the dealer, had to get an airbag recall done, and they spent time looking into my 172 code. Basically they verified the same stuff I did, fuel pressure, valve lash, egr, etc. They basically got to the point where they said that they'd replace the injectors. Replace all 4 injectors? Sounds fishy, but we're running out of options. I asked about the ECU. They just said that it is super rare for that to be the problem.

 

If I remember correctly the idle was higher than typical. Any comments from the dealer about that?

 

none, but they did comment that my map of .82 was lower than they'd like and after adhusting the valves they got .885, which was better....

joe

 

Lower MAP value is better (barometric pressure minus vacuum) so the higher vacuum (better engine) means lower reading of the MAP. So it will be better if it changes from 8.8 to 8.2 inches of mercury.
I've recently worked on 2002 Accord V-6 with dead coil. The MAP reading with misfire was 30 kPa at idle without load; it went down to 27 kPa after changing the coil (fixing misfire)

 

Funny, they insisted that closer to 9 was better. Maybe over tight exhaust valves could create more vacuum, but also the rich condition?

i have some oem rebuilt injectors on the way...

 

No, higher valve overlap will reduce an engine pumping ability at idle

 

 

I forgot to finally post my solution on here...

well, I'll say this, DO NOT just assume that your problem is mine. You can google the testing procedure. Do every test. Check MAP, fuel pressure, valve lash, etc.

For me it ended up being the injectors. Weird, but true.

 

Thank you for this informative thread. I created this account to just say that.

My car had the same P0172 trouble code, did all the testing with the information provided in this thread.

Two different local shops couldn't figure it out, but a set of remanufactured injectors from Rock auto fixed it.

(My car is a 2007 Honda Fit base model with a manual trans with 178k on it)