[hov333]

hey all,

such a coincidence, today i had my catless dp's installed. the car ran great all day. i get home to install my v3 and with the bypass plugs installed i turn on the car and start getting misfires after about a minute of idling. this continues to be an issue even with the entire proceed removed. funny thing is that i can make it go away if i rev it for a little. i took the car for a spin after the rough idle went away and it drove totally normal.

any suggestions? i want to be sure before i assume its HPFP. i rather know before i just drive into the dealer because that would mean that i have to go back into the shop to have my dp's removed.

btw code reader said i have cylinder 1 and 2 misfire. and one time it was 1, 2, and 3 all misfiring it said...

[scalbert]

The installers could have swapped the front O2 sensors. Open the hood and peek down and see it you can tell which sensors is on what turbo. The black cabled sensor shoudl be on the front turbo DP. You may need to let it cool and feel your way around to be sure as it can be decieving.

[OpenFlash]

+1 on the front o2 sensor swapped possibility. Will throw all sorts of misfire codes during idle. And the car will drive strangely under boost as well.

Shiv

[hov333]

thanks, i'll check tomoro and post back. Its funny because the car drove fine after the install of the DP. But yes i remember that i also saw some type of error code having to do with O2 sensor swap or something like that in the reader. i wonder why the rough idling and codes happen 1 min after startup and but didn't happen when i was driving earlier today. even regular idle after driving is normal. we'll see once i look at the sensors tomoro.

[hov333]

problem resolved!

solution: the O2 sensors which connect to the DP close to the turbo end were installed opposite. After swapping them around and clearing the codes, the car returned to normal.

[scalbert]

Originally Posted by hov333

problem resolved!

solution: the O2 sensors which connect to the DP close to the turbo end were installed opposite. After swapping them around and clearing the codes, the car returned to normal.

Glad to hear it was resolved.

[OpenFlash]

Originally Posted by hov333

thanks, i'll check tomoro and post back. Its funny because the car drove fine after the install of the DP. But yes i remember that i also saw some type of error code having to do with O2 sensor swap or something like that in the reader. i wonder why the rough idling and codes happen 1 min after startup and but didn't happen when i was driving earlier today. even regular idle after driving is normal. we'll see once i look at the sensors tomoro.

The rough running is caused by an uncontrolled oscillation event. The ECU is trying to correct for a something that it isn't actually seeing. The oscillation/roughness will only occur if one bank goes lean and the other one goes rich. If they are both rich, idle will be relatively okay. If they are both lean, same thing. So it's somewhat of a hit or miss as far as symptoms go. Also, it takes about a minute for the car to warm up and get to the point were the ECU has full fuel correction authority. Only when it has this, will it be able to throw it's weight around and get the car to act all silly.

Shiv

[jgalaxy]

Originally Posted by scalbert

The installers could have swapped the front O2 sensors. Open the hood and peek down and see it you can tell which sensors is on what turbo. The black cabled sensor shoudl be on the front turbo DP. You may need to let it cool and feel your way around to be sure as it can be decieving.

Can the cabling to the O2 sensors be visually spotted from above?

[scalbert]

Originally Posted by jgalaxy

Can the cabling to the O2 sensors be visually spotted from above?

Yes, but you may need to reach down and "feel" that the wire you see goes to which DP.

[hov333]

It was easier to get the car on a lift and remove the metal cover plate. This way not only it was easy to see but it was easy to correct.

On a side note, the car randomly (way later in the day) went into limp mode at one point which I wasn't able to replicate. I got the light on the dash but the car ran totally normal. Weird. Btw I wasn't driving the car hard. It happened while cruising. Procede isn't in the car yet either. Maybe just a freak thing who knows

[jgalaxy]

Originally Posted by hov333

It was easier to get the car on a lift and remove the metal cover plate. This way not only it was easy to see but it was easy to correct.

On a side note, the car randomly (way later in the day) went into limp mode at one point which I wasn't able to replicate. I got the light on the dash but the car ran totally normal. Weird. Btw I wasn't driving the car hard. It happened while cruising. Procede isn't in the car yet either. Maybe just a freak thing who knows

Strangest thing. This happened to me as well before I put in the JB3. Limp mode listed on the dash but boost gauge listed regular boost. Took half the day to go away. May also now explain my misfiring / surging sensation with the JB3 under boost.

I tried to see if I could see the cables, but I coudn't see boo with the oil catch can in the way. I need an oil change so I'll bring it in to the shop to have them take a look at the same time.

Thanks Hov and Scalbert.