Have u changed the belt recently? Was it ok one day then not the next? Is it more noticeable when the engine is hot? It sounds like a maf sensor but it may be worth checking things like fuel filter fuel pump delivery if the new maf doesn't fix it also if it does it when it is hot what plugs u running? They could break down when hot. Just chucking out some more ideas and hope u get it fixed soon which I'm sure u will it is starring u in the face laughing at you like these faults generally do!
|