After 60k - Still throws same codes: 172, 212, 215-217

[OrwellianChild]

Well, I feel like I only post when I've got an issue, but all of you have been great in walking me through my SHO issues... Here's the next step in the saga:

I'd been getting CELs on and off, culminating in a couple of engine stalls on the freeway... Upon recommendations from this forum, I did a 60k in-house (SPP Guide was very helpful, as was Fred for providing parts - thanks!). I swapped the water pump and gaskets, timing belt, crank seal, cam seals, Crank Pos. Sensor and Cam Position Sensor. Flushed the radiator fluid and swapped the lower rad. hose as well... The seal behind the Cam Pos. Sensor was bad, so I figured I had solved things by replacing them all.

No dice. I just got the above codes all over again. I'm wondering what my next move should be... Any suggestions? Thanks for all the help!

 

[OrwellianChild]

Oh... And I don't think it's related, but for completeness: I have a dancing tach needle... Under cruising conditions, it's just fine, but under load, it sometimes freaks out - it'll disengage and go dead, or it'll keep catching intermittently, making the needle spike repeatedly... More an annoyance than anything else, but I wouldn't mind fixing it along the way...

I drive a '94 ATX, btw... Red. (I'm sure that'll help with the troubleshooting)

 

[Yamaha V6]

172 is an O2 sensor (lean on right/ back bank). 60k will not resolve, must replace the O2, unless it is a vacuum leak. Since you had it before, let's assume O2 sensor, especially if the light comes on then goes off as you're driving.

212 is SPOUT circuit related. Make sure the gray jumper block / connector up in the back corner by the cam sensor on the wiring harness is intact / not corroded, etc.

215-217 are coil pack related.

a) Start by erasing the codes.
b) re-test the codes.
c) O2 is the one that comes on / goes off by itself as you're driving. The rest usually stay on if it trips the light.

With the tach bouncing, you've got something going on electrically - either the circuit / sensor truly is screwed or something's loose / corroded possibly. Double check the cam sensor, the DIS connections / grounds, and the crank sensor connector up top to start.

 

[projectSHO89]

Since none of those codes are likely to have been corrected by any "60K", it's not surprising they're still there.

All of your symptoms (exc 172) center around the DIS module and its inputs and outputs.

Verify power and ground integrity to the DIS module with a meter. Substitute a known good one or see if your local AutoZone can test yours.

172 is mostlikely due to your misfires.

Steve

 

[Yamaha V6]

Steve, if the O2 were misfire related, and he's getting banks of coils throwing errors, then he'd likely be getting both O2's throwing codes, no? He'd also be running rich, not lean.

I think the 172 is unrelated in this instance.

 

[projectSHO89]

Perhaps.

However, it is prudent to fix the known problem first then retest. It might turn out to be O2 sensors but the misfires have everything so screwed up that it's not really feasible to dignose anything further at this time.

Steve

 

[OrwellianChild]

Hey guys - thanks for the input... A couple of ?s:

The SPOUT circuit is part of the same plug you jump to pull codes, right? If so, it's in pretty good shape... Not sure what that means for the 212 code.

My cousin was driving when the CEL went off, and I wasn't there to see the behavior, but he said it lit while under load on a big hill near our house... Not sure if this helps... Would the O2 sensor cause any of the misfires, or is that a separate problem (in which case it's just the most recent)?

I'll have to see about getting my DIS checked - maybe Schucks or a NAPA outlet somewhere? (AutoZones are more scarce in Seattle) I'd love if it were as simple as that - I've got a blown head gasket on my other car (Dodge Neon R/T), so I've no shortage of car issues to take care of...

Oh, and anyone know where the sensor for the tach is located? Not sure where to start checking connections...

Thanks again!

 

[RStalveyARFF]

the SPOUT plug is near the EEC diagnostic port but it isn't that plug. The O2 sensor simply tells the engine whether that particular bank is running rich or lean. If you're having a misfire the thing isn't going to switch from rich to lean and it's going to make the computer think it's bad. I don't know about other parts stores testing parts. And finally, the sensor for your tach is actually one of the wires on the DIS.