Disconnect the connector and check the pins for corrosion. Also, as stated before, check if the wires going into the connector are in good condition by wiggling/gently tugging on them.

 

Note that it says to troubleshoot P0139 first. Also, not sure why your LTFT was normal as LTFT is computed as the average of STFT. In other words, after a while, you should have a high LTFT but the STFT should be closer to zero, in your specific case. Do not quote me on this. I do know with my older Civic that the criteria to set the P0171 was that the LTFT had to exceed +20%. Perhaps your freeze frame data showed a normal LTFT and high STFT because you had not driven for a long enough time.

 

Hmm, your diagram is much better, thanks! Okay, i checked the connector, looks good. The wire from the CKP sensor goes directly to the coils. I went ahead and replaced the CKP while I was down there. No change in symptoms. Thanks for the tip, it was worth a shot. I think I'm down to my fuel injectors again, but having a hard time accepting this since they were replaced earlier this year. My LTFT did start to creep up towards my STFT. Attached is a freeze frame from today.

 

Makes sense now that you got the code for a lean condition as the freeze frame data shows 19.5%. Not the 1-3% you listed before. It might be worthwhile trying to check the fuel pressure before having to pull out and replace the injectors. You need a couple of adapters but access to the fuel line connectors is not that bad. Am I correct in that when you replaced the injectors the first time, there was only a slight improvement? This seems to indicate that the original injectors were fine. I have also read that a lot o aftermarket injectors are not very good. Same for fuel pumps and ignition coils. I have 190,000 miles (306,000 km) on my Fit and it has the original fuel pump and injectors and ignition coils. Seems like coils and fuel pumps tend to fail far more often than injectors. It also seems unlikely that all four injectors are bad. You can test your old injectors by putting 12 volts to them and seeing if they click. Also check the resistance. Should be around 12 ohms.. You can clean them by attaching a hose to one end that you attach to a vacuum source on a (running) engine manifold and attach a hose to the other end and spray carb cleaner into the hose with the injector turned on by the 12 V source.
Can you see that I am grasping at straws here? I can send you a diagram of how to hook up a fuel pressure gauge if you like. Keep us posted.

 

My original problem was a no start which led me down the fuel delivery rabbit hole. The last thing I did was replace my fuel injectors and that is when my Fit started. I thought I was done, until my MIL came on with the P0171. Therefore, I must have had multiple issues. I think my fuel was the problem which has caused this headache. The Fuel Pump and Fuel Filter now installed are OEM. The fuel injectors are reconditioned/rebuilt OEM type. If my fuel tank is dirty, could this cause this multi-cylinder misfire lean condition? I can't think of anything else. I have the tool to clean and test my injectors, however before I get into all that, it would be nice to test the fuel pressure. I see the connector near the firewall, but I don't have the Honda adaptors/gauge to tap into that connector. I do have a fuel pressure test kit, but like I said, none of the adaptors fit the FIT. What say you?

 

I agree that your standard fuel pressure testing kit is not suitable for the Fit. Much easier with my 96 Civic. I think it should be possible to disconnect the fitting (see diagram) and this will give you one end to slip a tube over. The female side can possibly be removed from the hose and you can insert a brass hose barbed fitting into this and then with some tubing, connect this to a T fitting that connects to your fuel gauge. The other possibility would be to get both fittings off a car at the wreckers. I think that you would just need the female connector side but you could also cut the tube on the male side and use this to insert into the female connector on the car. I have included the diagram showing the location where you disconnect the fittings on the car and also the diagram showing the Honda set up to measure the fuel pressure.

 

CKP sensor is facing firewall, at 9 o'clock position on the crank pulley

 

Got it. Thanks!

 

So, a strange update. My fuel tank was a little over ¼ full and filled it up with 93 octane. Prior to fill up I added an Amsoil fuel treatment they sent free with an oil order. After I filled up, I monitored STFT & LTFT real time with the blue driver. By the time I got home the MIL turned off and my LTFT & STFT was 9.4%. At times my STFT dipped into the negative range. Lastly, what is the normal Cat temp? Mine was up to 1390F while driving and 880F at Idle. So, still confused but by the change in symptoms, I think I can rule out fuel pressure because I did nothing to improve it, outside of fill my tank. Any thoughts on this? Thanks.

 

So, a strange update. My fuel tank was a little over ¼ full and filled it up with 93 octane. Prior to fill up I added an Amsoil fuel treatment they sent free with an oil order. After I filled up, I monitored STFT & LTFT real time with the blue driver. By the time I got home the MIL turned off and my LTFT & STFT was 9.4%. At times my STFT dipped into the negative range. Lastly, what is the normal Cat temp? Mine was up to 1390F while driving and 880F at Idle. So, still confused but by the change in symptoms, I think I can rule out fuel pressure because I did nothing to improve it, outside of fill my tank. Any thoughts on this?

 

That is excellent news! BTW, total fuel trim is LT + ST, so the fact that you saw a negative ST fuel trim means that the LT will continue to drop. LT is the average of ST.
It is possible that the fuel additive has dissolved some gum/varnish that was restricting fuel flow. I know that the products that contain PEA (polyetheramine) actually work, and it is what is in Chevron gas (Techron additive) and in products like Gumout. Incidentally, I was looking under the hood of my Fit today to see where the fuel disconnect fittings were and I thought that it would be a royal PITA to have to check the fuel pressure.
Again, excellent news.

 

Not sure my problem is gone just yet, time will tell. I'm leaning towards an issue with a possible dirty/contaminated fuel tank. If my numbers get worse as my fuel tank decreases, I think that will be a tell. We'll see. The 1390F cat temp is suspicious to me. I don't know what a normal Cat Temp is while cruising.

 

I will take my Fit out for a drive and monitor the catalyst temperature and get back to you. This might be in a day or two.
Out of curiosity, why do you think that your fuel tank is so contaminated?

 

I just took my Fit out for a 10 minute drive with the scantool hooked up. Outside temp only 36 F. After about 5 minutes I accelerated hard a couple of times. Got up to 1345 F for the catalyst temp. So that is normal what you are seeing.
Thought more about your recent lower LTFT number. As much as I would like to believe that the fuel additive was solving the problem, they just usually do not work that quickly. So then I thought about the ethanol in most gas. A 10% blend (E10), which is typical, has 3.4% oxygen in it by weight and will give you a LTFT of 3.4% with all else being equal. E85 contains 28.9% oxygen (100% ethanol contains 34% by weight of oxygen, so 10% or 85% gives you 3.4 and 28.9% respectively). It is not unheard of for E10 not to have been blended properly and you get pockets of high concentration of ethanol. Or it was dispensed after E85 was dispensed and the hose contains a half gallon of E85. I would recommend that you continue to use the same location where you recently filled up with the 93 octane and see if your LTFT continues to drop.

 

Any chance also that E85 got put in your tank?

 

Thanks. On the recommendation of a friend and because I thought my Cat was acting up I used lacquer thinner in the tank. Big mistake. No doubt it was this that started me on this wild goose chase. The lacquer thinner might have done something to my fuel tank and/or system.

 

I don't think so. I fill up at Sam's. 93 Oxctane was all I saw. I'll go back and look again.

 

Thanks. Good to know. Nice breakdown of the fuel properties. I don't put much faith in the cleaner either. If my tank is the problem then a higher volume of high octane gas could change my symptoms. Curious to se what happens as fuel is depleted.

 

Modern lacquer thinner contains a lot of acetone. Pure acetone is 28 weight % oxygen so adding a lot of this to your tank would definitely boost your LTFT. So any solvent, be it ethanol, acetone etc that contains oxygen will boost your LTFT. Lacquer thinner could also strip any varnish off of your fuel tank and plug the fuel filter or injectors. Again, hopefully your LTFT number will continue to drop after the next fill up. BTW, I thought that I would see what the LTFT was for my Fit when I drove it tonight. -5.5% with the STFT being 3.1%, so -2.4% total. Negative fuel trims are far less common and can indicate a plugged air filter or a leaking injector(s).

 

You seem to know your chem. I suspected as much regarding the lacquer/ fuel tank varnish connection, which is why I think I need to clean it out. Thanks for the comparison tests, it helps to compare values with same vehicles. I'll post when I figure it out.