Please Help! P1320 Code

[AQuist68]

Hey everybody!
I've been reading and studying your site and all your great wealth of knowledge for quite a while now. I've used it to help solve the few problems I've come up against.

The problem i'm having now is something i've been researching for quite a while, but I'm not sure what to try next... I'm getting the P1320 code, but no other misfire code. I replaced all the coil packs, but it didn't help. It has a hesitation when its warmed up and I rev it to right around 1700rpms. If i slowly rev it to 1600-1700rpms, it will quickly drop back to about 1400rpms even though I keep the throttle on a constant amount. It then will keeps doing this over and over as long as I keep the throttle on the same amount. It's almost like there's a misfire or something, but i'm not getting any misfire codes. When I'm driving it I can drive around with it in that RPM range and I don't feel anything. I have no idea what it is... Somebody said possibly a crankshaft position sensor?
I'd love to hear what you guys think.
Thank you!

[asnorton44]

When you replaced coil packs did you also do spark plugs? Also try cleaning your MAF.

[AQuist68]

I didn't do the spark plugs... Think it could be those? I have replaced the MAF about 500 miles ago tho.

[asnorton44]

Yeah when you replace coils you want to put in new spark plugs. Get some NGK PLFR5A-11 (6240) spark plugs, shouldn't cost much around $50. As far as a bad crankshaft position sensor it should throw a code, I've had to replace both of mine at 175k.

[Towncivilian]

You can obtain 6 NGK PLFR5A-11 (6240) spark plugs for $40.54 + tax at Advance Auto Parts if you order online with discount code RETMENOT123 and pick-up in store. There is a guide on changing spark plugs here.

[AQuist68]

I'll give those a shot. Just curious, if I had a bad spark plug wouldn't it throw a misfire code for that specific cylinder?

[asnorton44]

Yeah it should throw a misfire code but they may just be dirty and that is what is causing the weird RPMs.

[AQuist68]

I ordered the spark plugs and am expecting them tomorrow. I'll switch them out on Saturday so I'm praying that fixes this problem... these should come already gapped correct?
Thanks,

[Azndjay]

ngk oem dont require gapping

[Chuck Tribolet]

But I always check them. I have a gapping tool I bought years ago that takes about ten seconds per plug.


Chuck

[AQuist68]

Well, I replaced the plugs today, but didn't help anything... It's still doing the same thing and sounding like it's missing when I hit about 1700 RPM's... any other ideas from anybody?