Missing on all cylinders

MLMMLM

MEMBER
2003 CADILLAC CTS
V8
FWD
AUTOMATIC

When I got the car It felt like a rough idle when parked or stopped
Driving home Monday the Check engine light came on
Checked for codes this is what I got
IPC U1301 History
IPM B0429 Current
IRC U1064 History
SDM B0041 History
SDM B0065

Took it to shop and they said no codes and changed plugs
Still doing it, to day light came back on and took it to AZ and said one code P0410
Brother looked under the hood and it looked like the big air hose wasnt all the way on he tighned it up and when I left for shop light wasnt on
Shop said no codes again But missing on all cylynders
The rough idle seems to come and go sometimes real noticable than other times

3 Replies

FACTORYJACK

MECHANIC
4,159 POSTS

You could possibly have poor fuel quality, or contamination in the tank. Does the poor run happen at any temperature(engine), or primarily when cold? Of the codes you given in your post, there is none that would illuminate the check engine light. The p0410 would illuminate it, it pertains to a secondary air fault, wouldn't necessarily cause a rough run.

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Friday, June 10th, 2011 AT 5:10 AM

MLMMLM

MEMBER
2 POSTS

Does it cooled or hot, had the car for about 6 months and its been doing it since I got it, sometimes you hardly notice it and other times it is really noticable, could the p0410 have been from the air hose that was not on right, I think when they did the plugs they didnt put it back on right, the light came on twice, once before they did the plugs and after the first time there was no codes the second was after when the hose wasnt on right so I think they were not related, I dont understand how it could be missing on all cyliners with no coses, I drove it today and no light came on

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Friday, June 10th, 2011 AT 10:08 PM

FACTORYJACK

MECHANIC
4,159 POSTS

The air hose, was it the breather pipe from the drivers side cam cover to the air inlet resonator? This should not give you a P0410, maybe more like a lean code p0171/p0174. For the system to set codes, there are several criteria that have to be met. If it is running as poorly as you are describing, I would expect you would see something. The check engine light does come on at key on, correct? The things to look at, and it would require a scan tool with data capability, are fuel trim and misfire counts. When an active failure is occurring, this could provide an indication of a specific cylinder, bank of cylinders, or all cylinders, experiencing problems.

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Monday, June 13th, 2011 AT 6:21 PM