Check Engine Light Popping

[UTEP]

Hi All,

Well I was running fine. Put ~150 miles on a new to me truck so I doubt the seller had reset it. He was an honest guy....

I put on a K&N cartridge filter and it popper the CEL right away..within a mile of driving. So I figure it's this and don't sweat it. I recall reading somewhere the computer will sort it out so don't panic just drive.

I then recall a way to reset the computer; pull EFI for 30-60 seconds and I did so this morning and it ran a little under power but eventually caught on and was fine.

Later I had some free time so I decided to change the spark plugs and clean the air horn. Went fine; no problems.

4R starts and runs much smoother with a noticable bump in power on FWY. But then CEL came back on after ~5 miles fwy driving.

Autozone scanned it and I got the "vague" PO171 code that could be a number of things...or nothing... Most commonly an O2 or MAF....

Does any of the work I performed suggest an issue I may have initiated?

I have to drive ~500 miles tomorrow.... any concern with this code?

Thanks,

Warren

 

[snivilous]

I wouldn't be concerned. I drove 150 miles with my CEL on and the same code (well later found out it was the same code, I was in the middle of nowhere when it turned on). I would check the MAF.

 

[zgensler31]

Clean the maf with the crc maf cleaner and also the throttle body. Its probably got quite a bit of carbon build up as is. The addition of the oily k&n fklter probably set it overthe edge. Its a somewhat common thing. Cel is probably justthe maf.

 

[DeathCougar]

If the CEL is on, there is an issue.

Likely the MAF has been coated from an over-oiled K&N filter. I see that happen all the time. Try cleaning the MAF using an electrical cleaning solution. If the CEL persists, you likely damaged the MAF and its time to replace it.

If you are in an emergency situation (such as middle of nowhere 150 miles, road trip etc) then it won't do much harm besides killing off MPG's. However, you will want to get that addressed asap.

 

[UTEP]

If the CEL is on, there is an issue.

Likely the MAF has been coated from an over-oiled K&N filter. I see that happen all the time. Try cleaning the MAF using an electrical cleaning solution. If the CEL persists, you likely damaged the MAF and its time to replace it.

If you are in an emergency situation (such as middle of nowhere 150 miles, road trip etc) then it won't do much harm besides killing off MPG's. However, you will want to get that addressed asap.

Thanks,

I had to make a 500 mile drive and just got back. Oddly I got 22.5mpg heading out and 18.2 mpg coming back. Same route for the most part. A few extra city miles but not that much. Same fuel Chevron 88 octane and I put a bottle of Techron in each tank.

I cleaned a MAF on my Tacoma once, same drill on the T4R? I bought some CRC MAF cleaner. I found a read a couple tutorials. Any other warnings tips?

Thanks,

Warren

 

[snivilous]

Thanks,

I had to make a 500 mile drive and just got back. Oddly I got 22.5mpg heading out and 18.2 mpg coming back. Same route for the most part. A few extra city miles but not that much. Same fuel Chevron 88 octane and I put a bottle of Techron in each tank.

I cleaned a MAF on my Tacoma once, same drill on the T4R? I bought some CRC MAF cleaner. I found a read a couple tutorials. Any other warnings tips?

Thanks,

Warren

When you unplug the MAF to clean it, unplug the battery too (while the MAF is unplugged) so the code will be erased so you'll know if that fixed it. Otherwise just the normal burst spraying and you're golden.

 

[UTEP]

When you unplug the MAF to clean it, unplug the battery too (while the MAF is unplugged) so the code will be erased so you'll know if that fixed it. Otherwise just the normal burst spraying and you're golden.

Yep,

I had to remove the entire filter box as the lower screw was stripped out and not wanting to repeat put a good 30 seconds of low pressure spray in it. I did this ~ 3 times; let it sit and work and come back a couple minutes later.

I pulled the EFI fuse instead and it reset the cel. All starts fine so far.

If you encounter the stripped screw from a previous owner I found a household electrical face plate screw close to or perfect match thread and length wise; this of course after your extraction method of choice, I drilled mine out. I was able to smoothly torque it in there and I should easily make it to the store for an exact size but I really like the fit....

I'll see how it goes...

Warren