New faults!!!!!!!!!!!!!!

[acano]

Hi all, left the house and the car started misfiring.
stuck it on VCDS which threw up these codes:

4 Faults Found:

16804 - Catalyst System: Bank 1: Efficiency Below Threshold

P0420 -- 001 -- Upper Limit Exceeded

17771 - Cylinder 3 Ignition Circuit: Short Circuit to Ground

P1363 -- 001 -- Upper Limit Exceeded

16697 - Misfire(s) Detected: Reason: Lack of Fuel

P0313 -- 001 -- Upper Limit Exceeded

16691 - Cylinder 7 Misfire Detected

P0307 -- 001 -- Upper Limit Exceeded


I know what the problems is with the first one (o2 sensor) but what about the rest?

thanks Tony

A4 2.0 SE 2001

 

[paul20v]

16804 - Catalyst System: Bank 1: Efficiency Below Threshold

P0420 -- 001 -- Upper Limit Exceeded

17771 - Cylinder 3 Ignition Circuit: Short Circuit to Ground

P1363 -- 001 -- Upper Limit Exceeded

16697 - Misfire(s) Detected: Reason: Lack of Fuel

P0313 -- 001 -- Upper Limit Exceeded

16691 - Cylinder 7 Misfire Detected

P0307 -- 001 -- Upper Limit Exceeded


Hi
i would be more inclined to say the first one is a cat efficiency problem
cylinder 3 ignition circuit sounds like a coil / ignition problem
as for a missfire on cylinder 7 thats a good one on a 4 pot

sort the first 2 out and you may find the others wont come back as a few fault codes are often symptoms and causes of others always go with the first ones that make sence to your symptoms
have you cleared the codes also to see what returns its always worth a try just incase theres old codes in there that somebody didnt erase after fixing previous faults
hope this helps
Paul

 

[acano]

I counted out the cat as I only just had it MOT'd and emissions were fine, thought the second one (17771 - Cylinder 3 Ignition Circuit: Short Circuit to Ground, P1363 -- 001 -- Upper Limit Exceeded) may be coil pack but wasn't sure and had no idea about the others.
I resently checked for fault codes (just before MOT) so it isnt any old codes left on there, so I'll buy new coil packs and see how it goes.

thanks for the reply Tony

 

[paul20v]

Hi
cats can still pass the mot but be out of there efficiency as far as the ecu is concerned as its out of its tolerences ,
ive got a customer who has had a cat efficency fault in his memory for 3 years and its still passing mots
he says he will change it when it fails the test
personally the light being on would annoy me also you dont know if any other faults come up as the light is always on
unless of course theres an obvious symptom such as a missfire which is unmissable
Paul

 

[1wheelonly]

ive had the same fault (16804 - Catalyst System: Bank 1: Efficiency Below Threshold ) for 2 mot's now, its deffo the cat, not the sensor, i changed the sensor in hope but didnt make any difference

 

[acano]

Thanks paul I never thought of that and your right clearing the fault and light for the cat is a pain, but always thought it was the sensor because of passing the emissions test, so looks like a new cat!
But it'll come after the coil packs now

Tony

 

[acano]

ive had the same fault (16804 - Catalyst System: Bank 1: Efficiency Below Threshold ) for 2 mot's now, its deffo the cat, not the sensor, i changed the sensor in hope but didnt make any difference

Oh well new cat it is then!
thanks Tony

 

[acano]

Right maybe someone can tell me why this is, I cleared the fault codes and its running as it was before the fault came, still slightly hesitant but nothing to bad. Would this be the coilpack and if so why would it be ok now? surely if it is faulty it wouldn't reset?

 

[paul20v]

Coil packs can be intermitent and will get worse when hot ,
you also have plugs and connections that are worth checking ,
im not saying the coil isnt at fault but sometimes the wiring or connections can be too blame everything is worth checking .

 

[NHN]

16691 - Cylinder 7 Misfire Detected

P0307 -- 001 -- Upper Limit Exceeded

A4 2.0 SE 2001

as for a missfire on cylinder 7 thats a good one on a 4 pot

That threw me too, strange huh

 

[acano]

Well a round trip of 60 miles and all feels fine, however still gonny change them! So would anyone know where the best place to buy replacement coil packs at a resonable price?

regards Tony

 

[johnnythepie]

you need to pm pjmspeedy