Hi all,

Wondering if anyone may be able to help with an issue I have been having, I have tried to include as much detail as possible but if anyone needs further info, just ask.

I have a 2013 Mercedes c250 (204) VIN - WDD2043032G075413

Couple weeks ago the car went into limp mode with a P0402 - EGR A Flow Excessive Detetced, clear the code but instantly came back, took to the garage who confirmed needed new egr valve and quoted me around £800.

I was also due to get the car re-mapped by a different company who said that they could do an EGR delete which would solve these issues, so I went for this option which was alot cheaper.

The EGR delete was performed yesterday, it has got rid of the above fault code and was out of limp mode. Howevere now after 5/10 mins of driving a new error code is coming up P2279 Intake air system leak back into limp/low power mode, although not as bad as the EGR limp mode, I can clear the code or even just turn the car off and back onthe car pulls fine again but then again after 5/10 minutes it goes into low power/limp mode again.

I contacted the company who did the remap who then said they advise plating the egr, if I had known this I probably wouldn't have had the egr delete as with my engine getting to the egr means stripping a whole load of stuff out and I am ok doing simple jobs but these more involved!

I have checked pipes and I can't see any obvious splits but I do hear a hissing noise front right, as i look, of engine. Not sure if this could be a pipe or if im just hearing something else and thinking its a pipe.

Im not really sure where to go with this now, could it be a split pipe or could the egr valve be slightly open and owuld cause this new error code to be shown.

Any help/ideas would be greatly appreciated, if any other info is needed, please just ask.

Thanks in advance

 

Normally remap spending is for increasing the performance from stock... repairs is mandatory for stock performance.....now is quite complicated to diagnose.

Your car may have functional EGR, but some air leakage that mess with HFM ( air flowmeter) calculation.

 

Going into limp mode is never fun, especially after you’ve already gone through the trouble of an EGR delete. The P0402 code indicating excessive flow and now the P2279 code for an intake air system leak certainly point to some underlying issues.

Since you’ve already checked for visible pipe damage and heard a hissing noise from the front right side of the engine, it’s likely that there’s a vacuum leak somewhere in the intake system. A split or loose hose can definitely cause the symptoms you’re experiencing, so I’d recommend inspecting all the hoses and connections in that area closely.

Additionally, if the EGR valve is still slightly open or malfunctioning, it could also contribute to the air intake issue, especially if the delete wasn’t fully effective. If you have access to a smoke machine or a similar tool, that can help identify any hidden leaks in the system.