Nissan Repair: catalytic converter, air mixture, nissan primera

Question
QUESTION: hey Calvin, i drive a 1991 nissan primera and i have recently had problems with my catalytic converter. the other day the car got progressively jerky as i was driving. it would struggle to accelerate, felt like the fuel was restricted (fuel pump was replaced a few years ago). even in 2nd gear i would put my foot down and there would be no change in the revs what so ever. after a long drive the catalytic converter light came on. i gutted the converter but still have the same problems. could it be the censor?
cheers Dan

ANSWER: Hi Daniel -

I don't think it is the O2 sensor, as it only monitors the fuel to air mixture in your exhaust.

You say the CC light came on, is this the check engine light? If so, I would have that diagnosed and the code read (OBD).

Also, when was the last time you had a tune up? Might want to take care of the obvious first.
Does the car run OK in other gears other than 2nd?

Let me know -
aloha
calvin


---------- FOLLOW-UP ----------

QUESTION: the light was definitly the catalytic converter light, not a check engine light. runs fine in all other gears, just an example at a low gear that putting my foot down doesnt even change the revs. tune up, not sure, to be fair it has done 320km. im going to disconnect the sensor from the converter and see how it runs without the sensor heating up. the problem occurs progressively after about 10mins of driving and continues to get worse, jarring and jerking, struggling to reach revs. any ideas? if this doesnt work ill just bite the bullet and take it to a mechanic

Answer
Hi Daniel -

When the CC light comes on it is usually because the converter has too much back pressure (clogged). If you gutted the converter, then it should not have this issue (might want to check some models have 2 converters). I was going to say disconnect the exhaust pipe at the manifold and see if the car runs OK uncapped. This will tell you if you have any restrictions in the exhaust system.

If you do take it to a mechanic, the first thing he is going to recommend is a tune up anyway, so you might want to start with that. I would just go ahead and replace the igniton module in the distributor as well.

This should save you a lot of money in the long run

Hope this helps -
aloha
calvin