cat

[mattd424]

ok my 95 3.1 is real slow startin off rpm's dont even go up barely till you let off the gas and press bck down.there is no smoking but was wonder if this could be a sign of my cat needs 2 b replaced.also at high revs very little exhaust is coming out the pipe.thank you

[JustSayGo]

Yes! Yes! Yes! You have identified an exhaust restriction that is most likely the catylitic converter.

[MT-2500]

Originally Posted by mattd424

ok my 95 3.1 is real slow startin off rpm's dont even go up barely till you let off the gas and press bck down.there is no smoking but was wonder if this could be a sign of my cat needs 2 b replaced.also at high revs very little exhaust is coming out the pipe.thank you

Slow starting may be another problem besides cat.
Any codes or check engine lights.
How is the tune up end?
A muffler shop or good repair shop can check the back pressure on cat to see if it is stopped up.
Or the back yard test is to open exhaust up before the cat and see it it runs better. Just watch that the exhaust does not get anything to hot.
Also a vacume gauge test at idle and at 2K RPM will show a stopped up cat.

Check Manifold Vacuum Install tachometer. Connect vacuum gauge to intake manifold vacuum source. Start engine and raise engine speed to 2000 RPM. Manifold vacuum should rise to more than 16 in. Hg. If manifold vacuum is okay, go to next step. If manifold vacuum is low, go to step 11). Leave tachometer and vacuum gauge connected. Start engine and raise engine speed to 2000 RPM. On a non- restricted system, manifold vacuum should quickly rise to normal range as increased RPM is maintained. On a restricted system, manifold vacuum will slowly rise to normal range as increased RPM is maintained. If manifold vacuum is okay, no indication of exhaust leak or restriction has been detected and testing is complete. If manifold vacuum is low or slow to respond, go to next step. Leave tachometer and vacuum gauge connected. Remove exhaust pipe from exhaust manifold. Start engineand raise engine speed to 2000 RPM. If manifold vacuum is now okay, fault is downstream from exhaust manifold. Reconnect exhaust pipe to exhaust manifold and go to next step. If manifold vacuum is still low or slow to respond, fault is in exhaust manifold or intake manifold gasket. Repair or replace as necessary and repeat QUICK TEST. Leave tachometer and vacuum gauge connected. Disconnect muffler/tailpipe assembly from rear of catalytic converter. Start engine and raise engine speed to 2000 RPM. If manifold vacuum is now okay, fault is in muffler/tailpipe assembly. Repair or replace as necessary and test drive vehicle to verify elimination of symptom. If manifold vacuum is still not okay, fault is in catalytic converter. Repair or replace as necessary. Check tailpipe/muffler assembly for debris from catalytic converter. Test drive vehicle to verify elimination of symptom.

Let us know how it goes.
MT

[mattd424]

thank you for the replies.this mornin i cut off the cat felt like it weighed a good 10 lbs.hung up the pipe.all i haft to do is weld the new one on right?i did a tune up bout 3 weeks ago with new coils n all since i had a bad 1.vaccume is good but i dont have a tach yet so i couldnt check it.the way it looked it looks like i just haft to weld on the new 1 is this correct?

[JustSayGo]

correct