hi all i have a lumpy engine it does not pull smooth from standstill misses then picks up ,,also it doesn,t feel right as you accelerate .. its a non turbo manual ,,i don,t know about this but the receipts for the new exhaust say the previous owner requested it be decatted and loud as poss which annoys me rather a lot to be truthfull so would that contribute to the lumpyness :mad::headvswal:headvswal:headvswal

Does it have the original airbox or an aftermarket filter? And does it do it after rain or all of the time? As if it has an aftermarket filter and does it when it is damp then it might be your MAF :( Other than that i can't help as i'm still a novice myself. HTH :)

thanks for your reply m8 but it does it continuously

Or could be sparkplug and/or coilpack! Just speaking from experience as these are always handy to keep an eye on! could be the connectors to them gone corroded or green! give them a clean and see if it improves! SImple fix if it is!

Maybe a knackered o2 sensor.

hi guys its in for a tune shortly so i will let you know the outcome thanks for all your input

The exhaust should not affect the performance at all except of course if the Cats are knackered. yours is decatted so not a problem. As above check the coil packs and the plugs especially if they have been in a long time. Also check the connectors / lead between the PTU and the CAS.