wazzurp

Well I have put up two breift topics on this but I will try to elaborate a little on this. I finally installed a VAFC II in my car this past weekend. After the initial install before tuning- everything else set to zero my Check Engine Light came on P-1259. It happened during decel from vtec to low cam. After checking over the wiring we didnt note anything wrong- but I changed my oil for precautionary measures- little low and about that time anyways. After tuning and during tuning the CEL went off a couple times but when tuned it stayed off until I was playing in and out of vtec and it went on again. The CEL only comes on when I am in and out of vtec very quickly. Any suggestions- I know the code sort of already and I tried to call honda and they told me to change my oil. Gotta love the techs.

Thanks

Steve

ChefJ

Refresh your MAP sensor. Check your vtec solenoid for voltage.
Check the vtec screen for oil blockage.
Recheck your wiring.
Check your oil pressure.

wazzurp

How do you refresh the MAP sensor.

ChefJ

unplug it spray it with some contact cleaner plug it back in and put a zip tie around it wit hsome super glue to keep it tight.

Slows2k

The MAP sensor WILL NOT cause this DTC. It's completely unrelated.

If your car did not throw this DTC before installing a VAFC, you can rle out mechanical causes.

The splices you made into the VTEC solenoid circuit or the VAFC VTEC switchover settings are causing the DTC.

The stock PCM is always monitoring VTEC solenoid and pressure switch inputs. When the solenoid is turned on, the pressure switch goes off.

If you VAFC is turning on the VTEC solenoid when the PCM is seeing solenoid OFF commanded, The PCM will also see VTEC Pressure switch OFF then you get the DTC. CEL comes on and no VTEC for you.

If you leave the VTEC settings alone and not screw with a VAFC, you'll never have the problem.

wazzurp

So Slows you say put the VTEC setting back to how they were normally- 6000 rpms and where should the low cam come on, or do you mean just dont mess with the VAFC II all together. I really need something to lean me out up to 11's were my AFRs before the tune and now I am in between 13.0 and 13.5 throughout the rev range.

Thanks Man

Slows2k

Moving the switchover RPM doesn't change the fuel or timing maps for the time the engine is in VTEC earlier than Honda designed. So by changing 1 output you are actually changing several things in how the engine runs.

I don't recommend changing it with a VAFC. For those that decide too, this is what they usually have to deal with.

If you keep dropping the VTEC switchover RPM you'll be dealing with this DTC. I'd rather have a car that always switches at 6-6200 than one that goes into backup and won't rev over 6K at all until you clear the DTC.

11.0's is too low a target AF ratio for a NA car at WOT as well. 12-12.5 is better.

ChefJ

What are you tuning for?? What are your mods??

Slows2k

Megan Header, T1R 63 mm with Berk Testpipe, K & N FIPK is in his Sig.

wazzurp

What I am saying is I was at 11 which is way toooooo rich so that is why I installed the VAFC II. I leaned my fuel line out to gain power. I def gained some power but this CEL is disturbing. My current AFRs are in the 13's based on several members AFRs with the VAFC II. The mods Slows listed are correct.