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in park no misfire.In gear 2,4,6 cylinders are misfiring and falling out, especially on a load.

have you tested compression or condition of spark plugs?

Compression is good,spark plugs are good.Would a vacuum leak from the plenum cause this problem,it sounds like its leaking bad.

crownvic wrote:Compression is good,spark plugs are good.Would a vacuum leak from the plenum cause this problem,it sounds like its leaking bad.

These intakes hiss alot anyway, but I wouldn't overlook it. Can you access fuel trim data and check the differences bank to bank?

I know about the hissing,this has a high pitch whistleing.bank 1 lt-9.0 bank 2 lt-32.0 in gear

crownvic wrote:I know about the hissing,this has a high pitch whistleing.bank 1 lt-9.0 bank 2 lt-32.0 in gear

Curious. It is higher on the side with the problem, but I would have expected it to be on the plus side, not removing fuel.

Are you sure those readings are negative readings?

In park bank 1 st0.0 lt-32.8 bank 2 st0.0 lt3.5
In gear bank 1 sto.o lt-2.5 bank 2 st0.0 lt-32.8

crownvic wrote:In park bank 1 st0.0 lt-32.8 bank 2 st0.0 lt3.5
In gear bank 1 sto.o lt-2.5 bank 2 st0.0 lt-32.8

Weird. Something is changing drastically when put into gear. I'd be looking at wiring harnesses, vac lines and intake boot. Something that could change if the engine is loaded. Weird.

Vacuum leak ?

That's what I initially thought, but the trims would be adding fuel, not taking away as posted.

Would a clogged converter cause this? The up strean o2 sensor is staying at 4.99 volts on that bank.

crownvic wrote:Would a clogged converter cause this? The up strean o2 sensor is staying at 4.99 volts on that bank.

Well, yeah. 4.99 volts is way too high for an o2!! That would make the computer take fuel away. I'm surprised you don't have an o2 code in it.

crownvic wrote:In park bank 1 st0.0 lt-32.8 bank 2 st0.0 lt3.5
In gear bank 1 sto.o lt-2.5 bank 2 st0.0 lt-32.8

+

I missed this. Yes check the o2's and convertor

I did finally get a o2 sensor code!!

yes, an intake leak will cause this problem. the pcm will try to richen the fuel and the o2 readings from bank one front and bank 2 front should be fairly close during warmup until it reaches operating temp. repair vac leak ten proceed. be wary of lean pop during acceleration. the leak could be the cause or the result of................