I cant find any info on this on the web after days searching and theorizing..
'92 EG Hatch.. just bought it
Has D15 swapped from a 93-94 coupe, 130k miles on motor, 240k on body.

I didnt disconnect any lines, I just drizzled 1/8th of a can into the manifold at 1/2 throttle, the motor died.. smoke came from the header area and the code threw for the O2 sensor.. I let the motor sit a bit.. cranked it up.. it idled low like it had been all along, of course it smoked like crazy.. then something let loose and it jumped up to a normal idle.. i felt accomplished!

Next day, and for the next 8 days so far... the motor stalls everytime the motor drops to idle like its starving for fuel.. every red light and stop sign..
It spits if you hold it at half throttle too..
I disconnect the MAP when i get mad at it, it runs fine once its getting the extra fuel.. but spits even wilder at half throttle.. otherwise runs great

I checked the IAC screen, its clean
Fuel Filter is new
Doesnt seem to be the fuel pump..
Not checked the sensor
And changed the spark plugs and the plug seals, cuz they were covered with oil bad..

This only started when the sea foam touched the motor..
Anybody know what happened?

 

I would check cat converter and the rest of exhaust system for any blockage.

 

I got it fixed at a performance shop. I had already known the car was not taken care of, and looked like it had been thrown together.
The stalling was caused by the rotor cap missing a screw in the distributor.. so it was not making good contact.. it was dying before, but only in morbidly hot weather.. ran fine at night.
Also found the tensioner bolt was missing on the alternator.. could move the alternator wherever you wanted. Half the exhaust is missing bolts including the exhaust manifold. The motor mounts are barely held on. The throttle cable was looser than cooked spaghetti.. the idle screw was completely closed.. im finding little things along the way.
The only thing left is to lower the idle back down a bit.. and figure out why the throttle hesitates so bad after the sea foam.. possibly the 02 sensor