2004 acura tl, rough engine, lost power, engine light on and as times VSA and yellow triangle.
Crankshaft position sensor B circuit intermittent. P0389. Multiple cylinders misfires.
CKP replaced, problem persist.
Any idea?

 

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If you have not already performed the CKP sensor relearn, give it a go:

 

Yes, no changes.

 

I'm thinking the replaced CKP sensor was aftermarket since OEM 37500-RCA-A01 is $328+?
Which brand did you go with?

 

No, sorry I bought the cheap one! But really I don't think it's that the problem. I already bought a looot of aftermarket parts for all my cars and never have problems with It.
An OEM sensor will cost more than my 2004 acura.
Sorry I think this is an " high enthusiastic forum" but my interest probably is only have a "funcional car. Thanks BDW.

 

I had a random misfire on my Camaro once. Turned out to be only 1 Fuel Injector. And I found it by using a mechanics stethoscope. Just put the stethoscope on the injector and you can tell if it is clicking or not. CLicking means it is working... Opening and Closing.
If not a fuel injector, it could be a cylinder with low pressure. I think the way the crank sensor works, it measures the acceleration of the crank when the injectors fire. And low pressure can cause a "low acceleration" as well. So it could be a few things that may cause that. But as for myself... i would start weith the easy stuff first like using a stetheschope if you have one.. If not, I think harbor frieght sells them..
Also make sure your spark plugs are tight.. For some crazy reason, cylinder #5 has been known to work its way loose. But check all of them, easy peazy

Free advice.... you know what they say... haha