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evest

Fault code help please

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Hello all,

 

Bit stumped - wonder if anyone can help me? Car is suffering a rough idle and also occasionally cutting out when coming of the throttle and coasting into a stop - not every time though; the revs sometimes dip almost to 0, and then jump back up to normal - other times the car will stall. I do have fault code P1283 which I know may relate to one of the upstream O2 sensors, but I'm not convinced (yet) that the sensor is necessarily the problem.

 

So apart from the car struggling at idle, particularly when coming of the throttle, I've sat and monitored the car at warm idle, as follows:

 

Car idles warm at about 8-900rpm which I believe is normal.  However, like clockwork every 10 seconds it dips to about 500-700rpm and struggles for 5 seconds before returning to normal. This also had an effect on the sensor readings:

(approximately)

Bank 1, sensor 1 = 0.25V (when idle rpm dips, this goes to 0)

Bank 1, sensor 2 = 0.75V (when rpm dips, this rises to about 0.9)

Bank 2, sensor 1 = 0.25V (as above, dips to 0)

Bank 2, sensor 2 = 0.75V (as above, rises to about 0.9)

 

It feels like the sensors are responding correctly, or at least working. My plugs were done about 25K miles ago. I recently cleaned the MAF sensor and I don't have any obvious signs of a vacuum leak. Do I have a fuelling issue - injectors? Car seems to be pulling fine at normal speed and acceleration has felt normal.

 

At the moment - I'm inclined to try a new MAF sensor and do all the reset procedures. Any clue from the info above though?

 

Car is a 2003 DE at 165K miles, using normal 5w30 oil. The only other thing I changed recently was putting in a HKS   filter (standard airbox).

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7 hours ago, evest said:

Hello all,

 

Bit stumped - wonder if anyone can help me? Car is suffering a rough idle and also occasionally cutting out when coming of the throttle and coasting into a stop - not every time though; the revs sometimes dip almost to 0, and then jump back up to normal - other times the car will stall. I do have fault code P1283 which I know may relate to one of the upstream O2 sensors, but I'm not convinced (yet) that the sensor is necessarily the problem.

 

So apart from the car struggling at idle, particularly when coming of the throttle, I've sat and monitored the car at warm idle, as follows:

 

Car idles warm at about 8-900rpm which I believe is normal.  However, like clockwork every 10 seconds it dips to about 500-700rpm and struggles for 5 seconds before returning to normal. This also had an effect on the sensor readings:

(approximately)

Bank 1, sensor 1 = 0.25V (when idle rpm dips, this goes to 0)

Bank 1, sensor 2 = 0.75V (when rpm dips, this rises to about 0.9)

Bank 2, sensor 1 = 0.25V (as above, dips to 0)

Bank 2, sensor 2 = 0.75V (as above, rises to about 0.9)

 

It feels like the sensors are responding correctly, or at least working. My plugs were done about 25K miles ago. I recently cleaned the MAF sensor and I don't have any obvious signs of a vacuum leak. Do I have a fuelling issue - injectors? Car seems to be pulling fine at normal speed and acceleration has felt normal.

 

At the moment - I'm inclined to try a new MAF sensor and do all the reset procedures. Any clue from the info above though?

 

Car is a 2003 DE at 165K miles, using normal 5w30 oil. The only other thing I changed recently was putting in a HKS   filter (standard airbox).

Hi there,

 

I had an issue where I had this same code relating to Bank 2 Sensor 1 pre cat sensor. I checked vacuum leaked etc and didn’t have anything. I didn’t want to pay £100+ on a genuine sensor to find out that it wasn’t the problem. 

 

Turns out, my issue was an exhaust leak between the cat and the exhaust manifold. The stock cats were on and the gasket had perished causing oxygen to enter and affect the sensor. This threw the code p1283 running lean on bank 2 as the sensor was detecting more oxygen in the exhaust than what was metered by the MAF. Saved myself £100+ by replacing the cats with TORQEN Decats ( was already going to do this ) and used new gaskets, holts gun gum and new bolts. 

 

I would suggest checking for these leaks first. Never had the code again since I sorted that out 

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Thanks mate, appreciate the input - I'll certainly replace the gaskets as they've been on there a few years.

 

Seems odd that a leak there would have this impact on the upstream sensor - but if it fixed your issue i guess it must do!

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No worries buddy. From my logic, I would think that when you're decelerating and letting the revs drop down, it pulls in some air through the leak thus changing the readings of the sensor.

 

I believe the sensor has to have detected over 80 miles or so that its running lean/rich ( Lean in our case ), before it triggers the EML.

 

I would definitely check them gaskets first :)

 

In terms of vaccum leaks, have you checked with a smoke machine?

 

 

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Just about to order them :thumbs:

 

No, no smoke machine, but will try that next. Thanks again, we'll see how it goes

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On 14/10/2019 at 12:33, fijifixit said:

I would definitely check them gaskets first :)

 

I think you were correct mate.

 

I replaced bank 2 gasket between manifold and cat. The old one was completely burnt through on one side.

 

Have done several journeys, few hundred miles, and the stalling problem has gone away. No EML and idle is normal. The P1283 had not returned.

 

Pending P1273 on bank 1 but I didn't have time to do that gasket - once I have I think this will be fully resolved.

 

Cheers! :thumbs:

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8 minutes ago, evest said:

I think you were correct mate.

 

I replaced bank 2 gasket between manifold and cat. The old one was completely burnt through on one side.

 

Have done several journeys, few hundred miles, and the stalling problem has gone away. No EML and idle is normal. The P1283 had not returned.

 

Pending P1273 on bank 1 but I didn't have time to do that gasket - once I have I think this will be fully resolved.

 

Cheers! :thumbs:

Glad to hear your problem is sorted! I got p1283 again couple months ago.. one of the cat bolts fell off Lool. All sealed up again and it’s gone away. 
 

Always cheaper to check gaskets first before forking out on a new OEM sensor :) 

 

Glad my faffing about helped! 

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Job done, second gasket replaced, should be in the clear now. Old vs new: 

 

This is driver side, not that bad compared to passenger side which was completely burnt through on one side.

 

20191110_132725.jpg

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