Why is car choking when accelerating?

remove the 02 sensor testdrive does the performance returns. start with what fixitmr said first

hi i ran it again tonight and its smoking as bad as ever i checked the pistons and there was oil on the top again i checked the compretion and its over 200 psi

sounds like a valve stem seals. how many cylinders show oil?

oil on all 4 cylinders the first head a changed all the stem seals it still smoked

if my oil control ring,s were knackerd would that explain oil on top of the pistons

are the plugs fouled and misfiring? what's the history on this problem? seems like low mileage for ring failure unless you are not original owner and it was mistreated?

hi the history is this i bought the car with some smoke on start up then it would clear my first thought was stem seals so i replaced all seals and gaskets +stem seals the smoking got worse so i did the same again still smoking so i changed the head ,the vales were dry when i put the new head on and yet again it smoked please help its driving me mad cheers mate...vinny

Since cylinder head has been done and redone a few times, guess you would have to look at the oil rings.
When replacing the head, was the intake manifolds soaked with oil?

Btw oil in the exhaust system takes some running time to clear and it could be up to a few hours of running.

inlet was wet so i disconnected the pcv so it could not draw oil in that way but it still smoked i have ran it the first time it cleared but the second time it did not but between me running the engine i changed the oil but just made it worse

Did you overfill the oil?
Excessive crankcase pressure can result in oil getting to the intake manifold. Was engine heavily sludged when you first worked on it?

not over filled oil but was sludge when i start work on this engine

Check PCV to see if it is clogged or heavily sludged.
On valve cover and engine block, check for other hoses or links from crankcase ventilation to the intake manifold. Ensure they are not clogged.

i diconected the pcv valve and ran the engine it made no difference i cleaned all the ports in the rocker cover still no change i made sure the oil was dropping back down into the sump im still scratching my head

Unless oil rings are very bad, otherwise they would not be leaving too much oil on the surface of the pistons.

Was the new head valve seals repalced and if yes, did you test if the valve seals were a tight fit?

i did not change stem seals on new head because they were dry when i fitted it and the company that i bought the head off offered me the coplete engine so i would think that there was no problem with the head and there was no sludge in the new head

That leaves you with the block components to work on.

yes and the only thing i can think of is oil control ring,s

Yes, there is no other components that can cause that.

i hope it is i have already spent 400 on this engine i have never come across this problem before but im not the only one its a big problem on the 2.0 mazda engine i have been searching you tube and its a big problem so thank,s for the advice mate ...vinny

You're welcome and good luck.

1 last question. with your web research was no culprit/ solution found?

yes it was found thank,s