what are the symptoms of plugged cats?

[Jonas Majauskas]

On Tue, 12 Aug 2003, bill bleiler wrote:

> Well.... I still havent seemed to figure out my
> problem. the car still starts and drives fine as long
> as you dont try to boost more than 3 lbs.   if you do
> the car surges as the boost rises and falls generally
> peaking at around 15 psi surging + - 3 psi,  although
> the dash display is displying the normal 1.9.  the car
> also will blow some black smoke in the higher rpm's if
> you get into the boost....could it be the cats? or the
> infamous MFTS? any input would be a help.

Do you see 1.9 bar in the dash display ? Then Motronic ECU thinks that you
have too much boost and tries to lower it. 1.8 bar limit is for OEM chip,
maybe be different if you are using "tuned" chip.

You know, pressure sensor is located in the Motronic ECU and then signal
is passed to dash display.