cliffcoggin

3% carbon monoxide is extraordinarily high. What was the CO level before you changed the induction system? The engine is getting on a bit at 175000 miles. What is the oil consumption? Does it smoke? Does it still have a functional EGR valve? Has the engine been modified in other ways?

I suggest you take the car elswhere for a second opinion before spending all that money. Unless the garage is using a professional code reader and knows how to interpret the results it could be leading you on a wild goose chase. The reason is that one fault can generate many unrelated false error codes, so it is essential the "technician" knows how to sort the wheat from the chaff. Even if the garage is convinced the ABS module is faulty I would ask for a guarantee that replacing it will eliminate the problem.

Kat. Who or what is telling you that the ABS module is faulty? The dashboard lamp, a proper VAGCOM diagnosis, a cheap code reader, a mechanic, or something else?

It could be a back tyre issue, or any of a dozen different issues from the sparse information you have provided. Whatever the cause, if you bought the car recently take it back to the dealer you bought it from.

Diane. Have you read the whole thread? There are suggestions near its start, and questions which would help all of us to home in on your problem.

Thanks for letting us know.

In your postion I would ask first the company what sort of guarantee it offers.

Musty. Sasidhar, like so many newcomers, has not visited the forum since posting his request for help four years ago. It's unlikely he will return now.

Dan. It would help if you gave some details of the engine such as its size and fuel.

Mark. As you suspect, the topic has been discussed many times here. It would pay you to search the forum to get some clues about your problem.

Indeed it is.

As I mentioned two days ago, "The battery needs to be coded to the car, otherwise you will get a variety of electronic faults and spurious alarms." I am not saying the lack of coding is definitely the cause of your problems, but until you eliminate that possibility there can be no logical resolution from error messages.

The EGR should last much longer than that, so I believe there is something else wrong with the car. Are you telling us the car has been remapped since it was manufactured?

Then your car must be unique. Every other A3 of that era needs the battery to be coded to the car.

The battery needs to be coded to the car, otherwise you will get a variety of electronic faults and spurious alarms. Sorry, but I will not download files from unknown sources.

Was the replacement battery new or secondhand? Did you get it coded to the car?

https://duckduckgo.com/?q=what+oil+to+use+for+a+AudiA3+Sportback+2019+1.0+Petrol&ia=web

Doesn't it tell you in the handbook in the car?

Glad to hear the problem has been resolved. Dare I ask who paid for the replacement engine? My speculation is that the old engine had been worked on in the past by somebody incompetant, who had either over-tightened the new cap bolts or re-used the old bolts, and at the same time somehow mis-aligned the oil pump drive. What that does not explain is why oil only leaked when the car was stationary.

A faulty valve spring is possible, but unlikely. More likely is a worn valve guide allowing oil and gases into the rocker case and crankcase. It appears you have the head off so now is a good chance to remove the valves and check their seats and guides.

Richard. I suspect a complete door, or components thereof, has been fitted from a different model. The previous wiring repairs complicate matters even more. What is not clear to me is what parts of the central locking are not working with which control units. The drivers door or the other doors? Using the key or the remote fob? It is possible the new controls need to be coded to the car, but I am unsure on this point.

Well who'd a thought it? Thanks.

I did not know a fuel temperature sensor existed on A3s. What is its purpose? I could understand diesel temperature being important in cold climates because diesel can throw a waxy sediment when it gets cold, but surely not in Newquay?

Richard. Before spending more money, check the wires in the door. It often happens that they break in the rubber bellows between door and frame.

More fouling of one valve than the others, plus the misfire on one cylinder, plus excessive EGR fouling suggests wear of the O-rings or bore. That's not altogether surprising on a twenty year old car. How many miles has it done? A compression test will be enlightening.