2001 2.4l nissan frontier does when accelerating

I just replaced the head gasket got the timing back together with the correct Mark’s on the chains started it up it idles surges a bit but will idle forever. When given gas it bogs out and wont go past 1200 at all. Originally when started up it was profusely shooting out white smoke out of the tailpipe and I checked the radiator no coolant leaks whatsoever. The rotor in the distributor lines up at 1 sparkplug at tdc. I’ve checked the fuel pump fuel pressure it’s good. Has great compression, Checked maf, iac, the tps all seems good one tiny vacuum leak but I dont imagine it would do this. Checked spark all good new plugs tried a new distributor nothing changes. I think the chains couldof gotten hot and stretched when the head gasket went out but I’m lost. Theres no visable slack in the chains either.

Remove the front O2 sensor and start the engine. If it revs well past 1200 rpm you likely have a plugged up converter. Be careful that the hot exhaust doesn’t damage anything.


You my friend are a life saver exactly the issue last thing I wouldof checked

It revs past 1200 rpm with sensor removed?

Yes it does what a relief

Good for you.