HELP- Missfiring 4AGE

[Adam_Cressi]

Hey all my mate has a problem with his smallport

So ive asked him to write down the problem he has.. just wondering if anyone can help

Ive had this problem with my ae92 fxgt smallport for 4 months or so.
It happend ever since i put the podfilter on and was told its fine to leave sensors dangling..
I had done it several times before, and it worked fine.. i always switched between the air-box and putting a pod on it.
I drove it on gravel road for some distance, then the car missfired only in high gears every 10 seconds..
Then the problem got worse and worse, and the engine cuts in and out as the check engine light flashes everytime it does it.

I opened the bonnet when it was missfiring for about a week, and found the resistor (that box on the flexi pipe) had fallen off leaving a big hole leading straight into the throttle-body.

The error code i get is 13 RPM signal, ive had the loom for the distributor done, replaced the ecu, Distributor cap, leads, spark plugs, coil
The problem keeps getting worse and worse, yet the car works fine in reverse!

Any suggestions what it could be, ive done a huge range of stuff..

Thanks guys hope u can help Ben out

[Adam_Cressi]

Sorry ben forgot to add also had the distributor replaced and the coil.

[timgte]

check for vacuum leaks.
the map sensor may be faulty or not getting a correct reading.