Can you provide more details; is the car warmed up or from cold, is it all the time or related to temperature of the day.

How many kms on the car?

What was done by the previous owner to remove the cat and DPF ? did they remove both ?

I always start by putting the car back to stock if you can. Sometimes modifications to the ECU will mask fault codes.

In my experience some of the ways that DPFs are deleted from the system result in other problems which are not easily found.

Also what country are you in, this also decides what model and ECU you probably have and who might have done the work.

 

Hi, Thanks for your reply.

It happens regardless of time of day and whether the engine is hot or cold. It happens in every gear. I can easily get the car to 70mph providing I keep the gear changed below 2000-3000rpm. When the car is kept below these revs it acts as normal.

The car has 113,000 miles (Approx 182,000 km) on it. The engine has been refurbished recently around 10,000 miles ago due to a rod bearing going.

I only noticed the DPF was removed when I had an Oxygen sensor go faulty. It appears there is a straight pipe welded in place of the Cat and DPF. The three sensors that usually sit in the Cat (Beginning, middle, end) have been removed and the wires are in a small box zip tied under the car (Haven't opened the box yet.).

There is a cigarette pack sized black box zip tied by the battery in the engine compartment. Upon opening it appears there is a USB port and a serial connector. The serial connector has been spliced into a wiring loom, with a white wire strung across the engine bay to an electrical connection on the left of the common rail system.

I am in the UK.

Hope this helps.

Thanks,
Pete