Hi everyone,

It's been a while on here since I last came to visit (sowwwy).

My car has developed the dreaded P1901-75 error code (limp mode, dpf blocked...).

At first I thought it could be the EGR valve, so cleaned that. Then the MAF wasn't well, so changed that... then changed the DPF pressure sensor, and checked all the hoses for split (none)...

The car worked brilliantly for about 1000 miles, and then boom it came back... and the DPF showed again the same silly code (even though I had driven 550 miles on motorway at constant speed - so the auto regen should have cleaned the DPF... but... I noticed that it couldn't have done so because for the auto regen to start, or the forced regen for that matter, it needs the temperature to be at 80 degrees minimum, and mine doesn't get to that when I drive as it's cooled by the air, and since it's faulty it doesn't register the correct temperature...

So when you have this dreaded code, check if the actual thermostat works/temperature sensor too.

In my case, everything is good, except that silly thermostat... So I am going to order one presto and then fit it equally as presto, as, luckily it's fairly easy to do on the 150 BHP engine (DTH)...

Thought I'd share my finding, because a lot of people on various forums talk of the code coming from the hoses, the EGR valve, the MAF, the DFP itself, the gas temperature sensors etc... but never about the thermostat... but no working thermostat equals no auto regen...