My Turn For The Infamous P0171 Code--And It WASN'T The PCV Elbow!

[TrainTrac]

I was driving home from work last night when all of a sudden, the Trac started to run really rough, but no CEL codes. Got her home safe and sound, planning to look into it today. After a quick visual inspection yielded no obvious problems, I took her out for another spin. This time, the CEL came on, and the Scan Gauge showed P0171.



I went back home and hopped on here for some research into that code. I didn't think it was the PCV elbow, 'cause I'd just replaced that whole hose/tube assembly last summer. I cleaned the MAF sensor and fired her up again. CEL reappeared, and she was still running rough.



Some of the folks who've had this problem in the past have reported here that the culprit was a bad coil. I have a PD Screamin' Demon coil on my Trac. So I yanked it off and re-installed the OEM coil. Took her for another test drive, and the problem's gone! Diagnosis: Bad Screamin' Demon coil.



This is the second SD coil pack that's gone bad on me. My first one crapped out over a year ago, but the fine folks at Zabteck were able to get me a replacement under warranty. Needless to say, with this second one now going bad, I'm staying with the OEM coil pack, and not using the SD pack anymore.

 

[Steve McKellop]

Seems most PCV elbow failures have the P0174 to go along with the P0171. That may be a pointer to a coil if you only get one code, IDK.



Glad you pinpointed so quickly though, thanks I'm sure to the great info on the site!:banana:

 

[Kevin Palmer]

Steve, that is a good point...

 

[scott degroot]

Steve M,12/19/2009 18:58 MT



Seems most PCV elbow failures have the P0174 to go along with the P0171. That may be a pointer to a coil if you only get one code, IDK.

NO. If you get a coil failure and it also causes a lean code it is going to depend on which cylinder is misfiring for the code to set. If it is cyl 1,3 or 5 then it will set a P0171, if it is 2,4 or 6 then a P0174 will set but if both sides of the coil go bad you could have both codes. What is extremely weird in this situation is that a P0300 or corresponding cylinder misfire code never set, I bet mode 6 data caught the misfire though.

 

[Steve McKellop]

That may be a pointer to a coil if you only get one code

I guess I didn't carry out the statement far enough to convey my intended idea. One or the other, individually, possibly a coil...probably not a cracked elbow. Both together, cracked elbow or as you say both sides of the coil. How common is that? This was just from observation as I haven't encountered either problem on mine....yet. :unsure:

 

[Todd Z]

What I don't like is seeing the PD coil go bad !!!! :angry:



I emailed PD, hopefully they have some answers.....



Todd Z

 

[Rodger Tellefson]

I have the ACCEL coil pak, before I had knowledge of the SD coil pak, in for a few yrs. now with no issues, yet.

 

[TrainTrac]

I hope you get some answers from PD, Todd. Have you heard from any other customers about problems w/the PD coil? Or is it just me?:smile0005:



Rodger (& Georgia),



I may look into the Accel coil pack, thanks.:smile0006:



Love the new smiley's Todd!!!:smile0006::smile0014::smile0015::smile0011:

 

[Todd Z]

Train...



Funny that accel came up... George and I both had them on our ST before we started selling PD....



BOTH of our coils failed within the first 6 months.....We warrantied them and went with the PD...



This is the 4th coil I know of, 2 I sold and 2 I did not....



IT could just be a rash of the older ones... all the failed coils were older ones..



Todd Z

 

[TrainTrac]

Hmm... Maybe I'll stay away from the Accel coils too.



As for your comment about failed coils being "older" ones, define "older". This latest one that failed on me wasn't very old. You guys warrantied my first one for this replacement about a year and a half ago.