cl55 slight engine miss

[3630stephen]

i know this is probably a stupid question but here we go anyway i had my cats checked over in longlife to find out that one of the primary cats is empty (the secondaries have been removed prior to me owning it) so i only have one functioning cat out of the two, now ive noticed only at idle that there is a slight imbalance in the engine ive checked all plugs and their all looking good so would the missing cat cause the imbalance ???

 

[Auto-mobile]

I'd be surprised, might be worth get the fault codes read, spark plug leads are really common on your engine, there are 16 of them and they breakdown overtime due to heat from the exhaust manifold that sits underneath.

 

[wu56Shoozz]

^ Wot He said. A misfire is usually on the HT side (High Tension) therefore I'd check both the leads and coil packs..

 

[3630stephen]

thanks guys i have an icarsoft mbii and im quite shocked that the cat isn't even flagging up the only fault code i get is the secondary air injection but that's only for emissions ill swap out the plugs n leads first and see where it takes me