Diagnostics recommendation

[cirks]

Our Mazda 5 may well have a failing DPF (has required more than one forced regeneration) but I'd like to actually get to the bottom of the issue which may be sensor related too and there is some uneveness in the running of the vehicle at specific speeds.

Can anyone therefore recommend a diagnostics firm in Herts/Beds/North London etc? Ideally, they could also do a rolling road or road test with diagnostics plugged in too

[cirks]

Superhoop said:

2.0??

Yes, 2.0l Sport

Many thanks for all the additional info too. The car went into limp mode 2 weeks ago in Wales and a regen was done then (DPF,TCS lights etc) but those have returned 900 miles later. It was replaced 2 years ago too when we had issues when travelling through France so had no real choice at the time other than the Mazda dealer to which we were recovered.
Definitely will investigate all - certainly the MAF has been stated as the possible issue when the last diagnostics were done a couple of months ago. So definitely interesting what you say about the EGR valve.
Will try to get someone to do the injector readings

Thanks again

[cirks]

Superhoop said:

Don't worry about the TCS light, it will be fault code C1119 - this pings up in the system with a number of engine management fault codes and will simply clear when the engine related codes are rectified - the most common code for throwing up C1119?? P0101, P0104 or both
These are both MAF codes and will be caused by the EGR valve sticking open.

Interesting I'll check the paperwork in a mo and see what codes were reported in Wales. Sensibly they gave us them when doing the regen

[cirks]

Qwert1e said:

Why not go to the local dealer and book your car in for "diagnostics only"?

as per above - they have stated MAF (despite previously being replaced <12k ago) and it has been cleaned etc. Car running hasn't been faultless despite the original replacement. I'm also not particularly keen to use either 'local dealer' again following previous experience with their work

[cirks]

By the time the regen was done the following codes were reported:
P0102- MAF Circuit low input
P0045 - Turbo Control Valve
P0104 - MAF Circuit Intermittent
P242F - DPF Restriction - Ash
P2458 - DPF Regen

[cirks]

Superhoop said:

P0102 & P0104 are MAF sensor codes. These are set due to the way the PCM (ECU) monitors EGR flow, the short(ish) version of which is:

Brilliant stuff. Thanks.
Is doing the EGR a feasible DIY job?

[cirks]

Superhoop said:

It's a pig to get off, and easy to damage if you don't know what you're doing. Where are you based?

Hertfordshire - Welwyn

[cirks]

and replied (thanks)