i have a V8 5.5 ML AMG and one side of the exhaust is blowing in the middle , so i was thinking of getting a dual 3" system but keeping the AMG oval back boxes but doing away with the cats, come MOt time in 10 months i will just switch it over to LPG and was wondering if the emissions woud be ok without the cats on LPG .....i have the option of fitting a spool piece and bolting the cats back in for MOt time if i need to .....are there any other things to consider ...i.e would the cat temp sensors need removing .....would it confuse the ECU etc etc

 

steve

no idea on the sensor + ecu side of it?? however on a normal LPG car it does not make any differene to the emissions if there's no cat. I know that from de-cating a lpg car myself.

 

Hopefully somone who knows a thing or two about mercs will come along and help you with the other bits, Maby not a bad idea to ask on some sort of merc or AMG forum though?

LPG limits are much higher for MOT purposes but you must let the tester know you are running on gas when you turn up - the vehicle needs to be tested with the fuel type as presented.

 

Heres the flow chart:

 

 

So if you go along to fuel type gas - then LPG you will see the typical non cat test limits are applied.

 

In my experience Mercs running non standard exhaust sound like shite unless they are using real expensive systems like Brabus or Carlsson! it completely changes them - the AMG's use higher flowing cats anyway.

 

Has the cat fractured? Often they split around the weld & you may be able to weld it back up again.

 

Paul

youll have no probs getting through the emissions with lpg on your vehicle so hack those cats out and gain some power.dont forget to tell mot tester its on lpg though..lee

thanks a lot guys , very very helpful Paul .....dont know how it ended up on the zed related forum though im sure i posted in the non zed related....my bad i supose .....im keeping the AMG tail pipes so hopefully wont loose too much of the burble but those cats have got to go

next its the manifolds..but at 125 quid a branch for custom made its a lot of wonga ..should release another 40 / 50 bhp though when its all done ......