Hi All,

Having on going problems with my skoda Octavia vrs, had it 5 months, fine at first then asr light kept going on, got code reader said maf sensor, replaced it all ok no faults running good, just for the hell of it i removed plastic engine cover, found y-pipe split but still running good, have now replaced this pipe and this is when the touble started, tick over is lumpy moves +/- 100rpm and when driving hard it losses boost you can feel it holding back, have also replaced pipe under manifold due to it spliting, new plugs ik20s and new coil packs x4 and new green temp sensor and replaced oil pickup strainer, engine oil and filter, I now need help in where to look next:

Is there a oil/breather blockage somewhere if so where do i look?

Should i remove y-pipe to see if normal running returns and is it safe to drive without it (how much oil loss would there be)?

Any help would be great,

Thanks in advance, Stuboy.

Edited 5 April, 201115 yr by Stuboy

Try cleaning the throttle body mate. Looks like the only thing you havent tryed. That should cure some of the lumpyness.

Thanks for the quick reply, i have cleaned it but only from the input side as i know i required a new gasket if i remove it fully, it looked clean anyway also removed and cleaned air intake temp sensor it also was clean, could the trottle body also be the boost problem.

As has been said, give the TB a really good clean with carb cleaner, using cotton wool buds and paper towels to wipe out all the black muck. Leave the wiring connected and get an assistant to put their foot on the throttle pedal to open the butterfly, then clean all the normally hidden surfaces.

You'd be surprised how much of a difference it makes.

If that doesn't work, then look at inspecting all the vac hoses under the inlet manifold, and replace any suspect looking hoses. You could temporarily fit a boost gauge, to see if you do have a vacuum leak. You should be pulling about 25inHg on a hot idle, so any less and you have a leak somewhere.

OK i will remove and clean fully as instructed (try and get new gasket today), also i have a vacuum gauge but where do i connect it and what should vacuum pressure be at tick over and how do i test for a leak??