So, I just got my Fit today. It has a code P0172, rich bank 1. I'm familiar with the code, but was curious if anyone had any other quick suggestions to check on aside from what the service manual recommends? Common problems that I should check first? I drive it 100 miles home and it was much faster than I expected it to be. Whatever is causing this code, it definitely is not hurting performance. 2 owners ago, the guy gutted the cat (and installed a CEL eliminator, not my preference, but it is what it is for now), put an aftermarket exhaust on, K&N air filter, etc. I'm almost curious if he tried one of those cheap "performance chips" that tweaks your MAF reading and makes it use more fuel. My fuel trims are both at -25ish. O2 cycles at .7v and lower once fan kicks on. That's all I've been able to look into for today. No idea what my gas mileage is yet.

Any suggestions?

 

I would look on engine coolant and air intake temperature sensor readings and compare them to ambient results (engine off, car cooled down overnight, using OBD II scanner with live data) If someone fooled the computer the reading will be highly unusual

Also read the freeze frame (condition when the code was set)
The map reading on idle (on my car is 27 to 28 kPa, 750 RPM in Park engine at 76 degrees C, accessories off, and 33 to 35 in brake + drive)

 

Thanks for the good info! I'll have to convert stuff into F for me.
​​​​​Mine is a manual, so it'll be a little bit different I assume. I'll check those. My plan is to clean the MAF and K&N filter to start. Probably good practice regardless. I may run some seafoam in the gas as well.

 

On 2007 there is no MAF; it has MAP; therefore mixture is not sensitive to additional air leaks or restricted intake; power output or idle speed are typically affected.
On the other hand, low fuel pressure or altered temperature sensors may change mixture and cause corrections (and codes).

 

Do later years have a MAF? I have only had the car a day and haven't looked at it closly yet, but elsewhere I read about people cleaning the MAF.

FSM suggested fuel pressure test first, which sounds like a good plan. I've seen people suggest checking the valve adjustment on it, which I'd rather hold off on until other things have been checked first.

 

IIRC, MAF is used on second(?) or third generation. 07-08 models using manifold pressure, engine temperature and intake air temperature to prepare the mixture. With M/T (gearbox in neutral clutch is released the MAP reading should be same as with A/T If all sensors are reporting correctly the advanced level software may be needed to check injection duration (opening time)

 

I'll check those readings tomorrow. Probably will still clean the air filter and add some seafoam while I'm at it. And then fuel pressure test ASAP.

 

Ok, I had 7.1Hg (24kpa) today in neutral and then the freeze frame showed 7.7Hg (26kpa) for the map sensor.

I also now have a code p0113, IAT circuit high input.

IAT was at 73 F in the freeze frame. 86 F this morning after driving around a bit and then sitting in neutral. Its about 33 F outside.

 

Also, online many people are suggesting to replace the coil packs. So, I feel like the car has great performance. But it does have 95k miles on it and I doubt they have been replaced. Should I just replace them, along with plugs, for maintenance? In the end I want this car to be reliable for when my wife drives it.

 

MAP readings look good. I got p0113, IAT circuit high input once I disconnected IAT sensor right after shutting the car off (the quote form manual says that the ECU still monitors sensors for a while AFTER ignition is turned OFF). If you saw this code after servicing your intake you may ignore it.
However check connector on it. The IAT sensor picks up higher than ambient temperatures after idling or heat soak. With car set overnight (8 to 12 hours) all sensors should read about the same. If you have a custom intake filter housing, the temperature difference may become more apparent.
I mentioned in my old posts, that P0172 code may pop out if there is a constant purge of fuel vapors into the intake but this situation happens during the hot weather (original poster never posted back, this is why some forum users are suck!)
It may sound silly, but I would put factory intake cleaner with Purolator filter and see what happens.
Many coils are dying because of high heat; so in colder climates they may last longer. You can change them if you wand but don't put chap ones in there. I got 2 extra factory coils (Honda pn 30520-PWC-S01 with about 10 k miles on them) and may be willing to sell those for a low price.

 

Well, I cleared the codes and went for a drive. The light didn't come back on, but after driving for 10 minutes my fuel trims wete showing that I'm rich. Stft -20% ltft -5%.

I will say that I now think I'm noticing a misfire. Just cruising at 20mph in 3rd gear I feel little sputters. I've really only been on the freeway up unti now, so maybe I am misfiring some. I'll do the full tune up and then report back.

 

It may be a good idea to perform check on evaporative control system (to rule out high purge flow, although it unlikely to have this issue in winter)
in theory, continuous misfire will make FT about +10%, but not -20%
what were the 3 temperature sensor readings before you started car?

 

I forgot to check, but will now... i need to make a quick run.

 

 

Not trying to derail this discussion, but may I ask what tool you guys are using to get all of these Error codes? My wife has an 08 Fit that runs okay, but I know the valve clearance needs to be adjusted, and who knows what other kind of problems it may be having. I feel like we could get some better mileage out of it if I could read some of these error codes.

Thanks in advance.

 

Well, above is a screenshot of the android app Torque, using a $12 obd2 Bluetooth adapter off of Amazon. It does well, but earlier I was getting info off of my Mac Tools Scanner. That's a much more expensive device.

If you have no check engine light, you won't have any active codes. Perhaps a pending code which hasnt set the light off yet. But for you, the cheap Bluetooth device is the way to go. I would buy one for every car I own that is 96 or newer. Just leave them installed.

I'll be checking my temps on an ice cold car here in a minute.

Doc, you mentioned 3 temps? IAT, ECT, and...? Ambient? Or just checking the MAP with the engine off?

I'll have to drive the grueling 500m to my shop before I can check with the Mac scanner again...

 

Thanks for the quick reply. I think the only Android device I have is a Kindle Fire. Might have to play round with that. Probably a similar app on the iOS store. Looks like there is still some information to gain from the app, even without any engine error codes.

 

Yeah, I'm sure there are lots of apps if you don't mind spending a few bucks. Torque has a free version that works great.

The same Bluetooth reader will work on either. Amazon or eBay. I would not spend more than $14, they're all the same.


ooh, and all of my temps were even this morning.

 

The IAT reading is almost withing 5 degrees F from ECT so the sensors are good.I would also check if there is any oil is entering the engine (via PCV system or from the lubricated air filter element (if applicable). The spark plugs will likely look normal color because computer still able to correct the mixture (but close to maxing out).

 

Ok, so my plugs looked good.

New problem, my Lisle Master Fuel Pressure Kit doesn't seem to have the correct fittings to test the fuel pressure! I looked at everything.

Any idea what fitting I need. I'll go Google some more, no luck earlier on my phone.