Catalytic converter removal

[mycomitan]

I live in an area where the cat converter is not required, So I removed it, put on a new muffler, exited in front of rear wheels, Now I've lost a ton of power takes for ever to get to 55MPH, should this be, the same day I had the A/C fixed I'm just wonering if they disconnected something and didn't put it back, don't see any vacuum lines out of place. Any help out there.

1987 Dolphin

22RE engine

Edited May 16, 2007 by mycomitan

[keitholivier]

Does your vehicle have 1 oxygen sensor or 2 ? The first is fitted into the exhaust manifold. On my Dolphin (85 Chassis, non California) I only have the first sensor. Some later models (and most modern vehicles) have a second sensor after the catalytic converter. The first sensor provides a coarse indication of whether the air/fuel ratio is stochiometric. The catalyst reacts unburnt hydrocarbons, oxidizes CO to CO2 and NO to NO2. Generally, if the catalyst is functioning, the second O2 sensor downstream provides a confirmation of proper function.

In a system of the first type (just 1 O2 sensor) the ECU operates in closed loop mode (continuously adjusting air/fuel ratio to keep it at the stochiometric point), but has no feedback regarding function of the emission control system. In the second system the downstream O2 sensor provides feedback on function regarding performance of the catalytic converter. If you remove the catalytic converter in this type of system the lack of conversion function will be detected (which it was designed to do).

Now I have no idea in the case of this ECU what the reaction is to failure of the emission system, but it is possible that the default is to run rich (since it is less likely to cause damage to the engine). Running rich is normally not that bad for performance, but can increase fuel consumption significantly.

So here you have one possible outcome (running rich). Your "Check engine" light should illuminate. Another possibility is that something went wrong when the new muffler was fitted. Perhaps the system is somehow restricted or the new muffler has a blockage. This will certainly reduce the performance significantly.

[mycomitan]

Keith

You may be on the right track with the O2 sensor they welded on a leak close to the sensor, so will change and see what happens.

[86rader]

you now have a considerably shorter less restrictive exhaust. Sometimes this is a bad thing. In particular, low end torque can be affected adversely by this on some vehicles.