07 Honda Fit Base Automatic | 212,000 mi | 24-28 MPG | used from a private party
About 6 months ago dash kept showing "check fuel cap" so I replaced the cap and it solved the problem.
About 4 months ago I took the car to the shop for regular maintenance, valve adjustment, new spark plugs... everything was clear.
About 3 months ago check engine light was on, I took it to AutoZone and the code was P0303 cyl 3 misfire detected. The light went off after a couple of trips so I thought it was just a one-time thing and did not do anything. Nothing felt wrong.
Last week the light was on again, same code and the car ran fine except the car sometimes took one more crank to start (normally starts at the 5th crank, now 6th). I bought 4 remanufactured injectors from Autozone and took the car to the shop and they changed them. Code cleared and the car ran fine.
Just a couple of trips after new injectors were installed, the light came on again with a new code P0172 Bank 1 too rich. Autozone report recommended a new EGR valve and gasket so I CLEANED the valve and replaced the gasket. Problem NOT solved. The car runs fine except that sometimes it starts on the 2nd crank instead of the 5th.
I bought a THINKCAR 100 reader and a few things caught my attention:
SHRTFT1 ~-30%
LONGFT1 ~-20%
O2 sensor fixed at 0.7V
EGR_PCT 0%
EGR_ERR 99%
I/M Readiness
O2, CAT, EGR INC (incomplete/not ready?)
What is the problem? Bad injectors? Bad EGR valve? Bad O2 sensor?
Thank you!!
-Enoch
Just to clear things up a little. When I said the car normally started on the 5th crank, I didn't mean the 5th try but the 5th click/crank when I turned and held the key. The car has always started on the first attempt.
You should have used OEM parts.
Sigh... Well, I still have the original set of injectors, should I try swapping them back?
There are so many parameters here that seem to be out of range. Start with MAF sensor reading.
I read that 07 Fit only has a MAP sensor? Anyways, MAP reads 9.0 inHg at idle (900 rpm; ECT = 138F).
You are correct. It does not have MAF sensor. The MAP reading seems to be Ok. The issses you have could be due to the fualty injectors. As @doc said, use OEM injectors. About the I/M readiness, did you clear the code after you replaced the injectors?
Also, you have low mpg and considering the fact that you have a long cranking to start the car as well as the fuel trim numbers, suggest that you can have bad injectors.
One thing that stands out from that data is the computer is commanding the EGR Valve to Close (EGR_PCT 0%).
But the computer is receiving a voltage signal from the potentiometer on the EGR Valve that the EGR Valve isn't closed (EGR_ERR 99%).
The EGR_ERR formula is,
(Actual EGR Position − Commanded EGR) ÷ Commanded EGR = EGR Error.
But in your case the computer is commanding 0% and if I remember my 6th grade math right, dividing by 0 doesn't work so that's why the computer is defaulting to an EGR_ERR of 99%. It wants the EGR Valve closed all the way and it isn't closed all the way (according to its input from the egr sensor voltage) and it can't do the math either.
What's the computer going to do if it believes the EGR_ERR data?
The EGR data alone means that non-combustible exhaust gases are displacing air (oxygen) in the combustion chambers (when they shouldn't be because the computer has commanded the EGR valve to close).
It looks like the AF sensor is confirming that the O2 level is low in the exhaust if that 0.7 volts is actually the data from the (upstream) AF sensor. (it's way out of range).
The computer sees a Rich condition and the result is those high negative fuel trims as the computer attempts to maintain the 14.7:1 (air:fuel) ratio.
But there's yet another thing in the mix. Those remanufactured fuel injectors.
Is one or more of those remanufactured injectors leaking?
First, you may want to confirm the AF sensor is responding by forcing a lean condition.
Hook up the scanner on Live Data (Datastream) and observe the AF sensor voltage and the fuel trims as you force a Lean condition by disconnecting a vacuum line.
The AF sensor's displayed voltage should rise in response to the lean condition.
If that happens then maybe hook up a fuel gauge and observe the fuel pressure drop after you turn the car off. It shouldn't drop quickly If it does that could be a leaky injector.
If the pressure drop is within time specs, that brings you back to the EGR valve (electrical issue, not dirty).
Not really sure if the reason you replaced the fuel injectors was just because of the P0303 code and that it took a little longer to start than usual or if there was another reason.
If there was another reason that may be helpful in figuring this out.
I also replaced the air filter (dry) but it didn't help.