2002 golf gti 2.0 po420 fault

Question

ive replaced the cat and ho2s2 and still have the same problem

checked for ex leaks,cleaned throttle body and checked for vacuum leaks etc
still have the fault code

Answer 1

Hi there,

Here is a list of possible causes for this code.

P0420 VOLKSWAGEN - Catalyst System Efficiency Below Threshold Bank 1

Read more: https://www.autocodes.com/p0420_volkswagen.html