ive been driving my car around today and out of the blue it just started to run crap, the tickover has gone all rough and it wont rev past 3k. my first thought was the maff but i disconnected it and the car started to run even worse and cut out so its not the maff, ive checked the ecu codes and 23 came up which is maff but thats prob because i disconnected it, code 22 also came up which is the knock sensor. would this be a faulty sensor or would it of detected knock? any help is apreciated.

 

ok ive just been out and reset the ecu and code 22 had cleared but code 23(maff) is still flashing so ive diconnected the maff connector again and there is no change in the engine revs for a good few seconds and then it cut out. ive checked the codes again and 22(knock sensor) and 23(maff) are back flashing.

 

would it be to much of a coincidence for the maf and the knock sensor to go at the same time? also,would the car run as bad as it is doing with just the knock sensor gone because im sure the maf was fine when i first tested it.

 

I had both go on mine at the same time, put this down to water coming in through the bonnet scoop since I have a FMIC. Both replaced and connections sprayed with WD40, no problems since.

The knock sensor wouldn't make it run bad, just wouldn't retard the ingnition if knock was present.

Change the Maf and reset ECU again

I have to say the Knock sensor was a complete b4stard to change due to it's location, took a couple of minutes to remove and about an hour to get the bolt back in!!!!

 

cheers mate, ive just ordered the new sensors, i;ll change them and reset the ecu, how long does the ecu take to lean again? do i have to gradually build up the boost ect?

 

I think you drive at around 3000rpm (motorway cruise) for 10 mins or so and it does the rest

 

just disconnect the battery while you spend an hour getting the knock sensor bolt back in

that should reset it fine

 

problem sorted. ive changed the knock and maff sensor whilst the battery has been disconnected for a couple of hours, car runs perfect now and there are no falts on the ecu.
The only thing i need to know is how long the ecu takes to get back to normal after the reset. Ive just drove about 6miles and put some fresh v-power in, do i just need to drive it normally and and slowly work it back up? how long does this take? thanks for the help.

 

Nope it should be fine, Once the ecu has been reset, which is what you've done by disconnecting the battery.

How did you get on bolting the knock sensor back on???

 

cheers, the knock sensor was a bas**rd to get back in, i used one of those flexi grab thingys in the end that you use to pick up dropped bolts and stuff, it went in fine with that.

 

I'm glad I wasn't the only one to have a problem, We did mine on the the slip road on the M4 near swindon!!!!! took nearly an hour just to line the bolt up, talk about a stupid place to mount it, you just can't get your hands on it. and the sensor being banana shaped doesn't help

 

i did my knock sensor this morning and i was done and dusted within an hour easy, in fact i think it took around 30 mins as i remember watching the tv at work and having a cupper after i finished.

i used a dab of hot glue to stick the bolt into my socket, once the water pipes were out the way i was laughing ??

 

i just had a knock fault code 22, car been stood for a few weeks in the cold damp air, removed sensor, dried it off with a hairdrier , problem solved! maybe some moisture got in there and was throwing a fault reading!

 

It is the maf I would say, its running on the speed/density fuel matrix which chokes it past 3k. Its a falacy to think that a car won't run with the maf disconneced, ecu has specific maps to allow it to do so. It just runs pants !!

bob