[Nail Grease]

Ok, I could use a little advice.
A couple of weeks ago, my 2012 V6 Crosstour with 267k miles popped a P0304 Code, misfire cylinder 4. Checked fuel trims, Bank 2 fuel trims were way negative (lean) while Bank 1 was normal near -0+. So everything I read, figured I needed an injector. I decided to replace all the injectors while I was in there. After I replaced the injectors (Genuine Honda). It was improved, but I knew it still wasn't right. Today the scanner showed not only P0304 but P0300. Again, fuel trims for Bank 1 are normal, Bank 2 👎.
Where would you go from here.

 

[Nail Grease]

Maybe one or both oxygen sensors for bank 2?

No O2 sensor code. ?

 

[Nail Grease]

are the coils and plugs good? When was the last time the valves were adjusted?

The engine was running smooth as silk 3 weeks ago. I have no reason to believe it needs a valve adjustment, it has been a while.
I can lift coils off each plug and the engine will faulter.
Would any of these two things cause abnormal fuel trims on Bank 2?

 

[Nail Grease]

What sensors, actuators, switches, vacuum lines and/or electrical connections are unique to bank 2?

Definitely electrical conections to injectors for bank 2. Need to check each one.
The mosquito invasion started, shut the garage and in for the night. Had enough.

 

[Nail Grease]

What effect would a valve not closing all the way have on fuel trims?

From what I've read, it would be a problem.

Looking at the freeze data, what was the coolant temp, map reading, and rpm when the code was set?

I dunno. Never saw the engine light come on. I drove it 65 miles at 75mph, thought I'd check fuel trims and see if it was doing any better and discovered the pending misfire codes. When parked at 730 rpms with no CEL...
ECT 191°
MAP 9
MAF .62
STFT B1 -0.8
LTFT B1 -3.1
STFT B2 -7.0
LTFT B2 -9.4

 

[Nail Grease]

It is, I am asking what do you believe raw fuel leaking past a valve would show on your trims?

What I've read is it would cause negative fuel trims.
I guess my doubts come because my Bank 2 fuel trims were as good or better than Bank 1 before the trouble began 3-4 weeks ago.

That data was at 730rpm?

Yes.

 

[Nail Grease]

Not saying it is a valve, but negative trim is the result.
If your map is indicating 9 inches of vac at idle, that's very low. It should be between 15-19 generally, this is where I would start. Your b2 trims indicates a total of 16.4% fuel is being removed from b2. Focus on vac leaks there, live graph your b2 a/f sensor and start spraying your intake,hoses, injector seals. You'll see it in the graph if spray across the leak.

Thanks for the MAP info!

 

[Nail Grease]

Quick question,was your map data in volts as in .90v or was it inches of vac?

inHG
Did some reading last night about brake booster vacuum loss. I dont recall having any problem with brake pedal tho.

 

[Nail Grease]

Time for some berryman chemtool b12 and some coil boots x6 (rockauto or napa - just make sure to get the ones with the springs inside). I replaced them recently and no more dreaded misfire codes.

As mentioned, installed 6 new OEM injectors with new fuel rail O-rings.
The coils on this 268k mile vehicle came off my other Crosstour that had 103k miles. So at the most, these coils have less than 120k on them. Did a coil swap between cylinders, misfire remained on cylinder 4. Experiencing lean fuel trim on Bank 2. I'm hoping it's a vacuum leak, but I'm not ruling out a loss of compression in that cylinder. When I get the vehicle back, I'll be looking for these, and doing a compression test. Hope for the best, fear the worst.

 

[Nail Grease]

Well I'm happy to report that my compression test on all 6 cylinders proved to be good! Especially cylinder #4 where my misfire code was 😁. Nothing below 120 psi after 3 strokes.

 

[Nail Grease]

I have not detected any vacuum leak using butane around vacuum hoses. Disconnected the brake booster vac hose and plugged it. No change in the map reading so I do not suspect the brake booster. No trouble with brakes either. Replaced intake manifold gasket and throttle body gasket, the air intake hose is leak free, no change in the MAP reading. I can not hear a vacuum leak. Replace MAP sensor?

 

[Nail Grease]

Have a manual vac gauge? What does your scanner show for map voltage at hot idle, maybe your scanner isn't reporting psi correctly.

No.
Going to see what my MAP reading is on my other Crosstour. May swap sensors to see if the reading changes.

 

[Nail Grease]

Fuel rail or fuel pressure regulator?

This and the fuel pump seems to be my next jump.

 

[Nail Grease]

Fuel pump would effect trims on both banks. Things that are the usual causes of 1 bank trims being off
A. Cam timing off
B. Vac leak
C egr ports plugged and egr not closing all the way
D. A/f sensor biased
E. Cat being plugged/restricted
F. Valve on the bank out of adjustment
G injector(s)
H. Have seen cracked air intake tube on a maf veh effect only 1 bank.
Map v would be helpful information

Ty for the list.
I am suspicious that the EGR may be the problem.
I checked the MAP reading on my other Crosstour. The reading is the same and has very negative fuel trims, but both banks. 🤦‍♂️

 

[Nail Grease]

Welp, after going over this engine, and unable to find a vacuum leak to attribute to negative fuel trims. I'm pleased to say that after buying a professional scan tool, I was able to reset the throttle, and my fuel trims are back closer to zero. It smoothed out instantly! It's not dead yet! 😁
After the compression test checking out great and its smooth again at 268k... This is definitely a banana dance moment!

New radiator and AC condenser going in this week, hopefully back on the road next week.

 

[Nail Grease]

Which scan tool did you buy?

AUTEL
MaxiCOM MK808TS

 

[Nail Grease]

View attachment 149512
Autel?
Oh well.
One less kickback
from Foxwell.

I couldn't bring myself to buy a scanner off Fleabay.

 

[Nail Grease]

What happens when you hit hogs. 🤦‍♂️

Pushed in on the bottom passenger side about 3 inches.

 

[Nail Grease]

Little bangin here, a little there. Large vice grips to bend metal straight again. Got it to where the radiator and condenser can sit in their cradle again. Little touch up primer, looks new again. At least until the next hog strike. 🤦‍♂️
🐖🐖🐖🐖🐖

 

[Nail Grease]

The computer dating service matched up a lonely DIY auto mechanic from TX with a comprehensive diagnosis companion.
The relationship will be platonic and wireless.

🤔 Hmm. Don't think this analogy will work for me.