evest

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!

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).