Hi gang, hope you are all doing well? I think was thinking about this the other day. I'm not really getting any cel codes, not sulphuric smell from exhaust. Sometimes at highway speeds i'm not sure if it's the state of the road itself, but feel a slight "jerky" motion.
i decided to take a laser thermometer and check temps of the secondary car (one before the muffler , under passenger seat). The engine was warmed up and at idle. I tested pipe section before cat, and was around 190-200 celsius. I then tested at centre section of cat AS well as pipe after cat and they were around 160-169 degrees celsius. Is this normal? Does this sound like a healthy cat?

 

Are you sure it is a cat? Some models/markets have a resonator there I think...

 

Mesquite.....
yes, it's the secondary Cat. Basically...the two cars meet at the collector...which has a flange. The next section is a flange followed by the secondary cat (no 02 sensors). After this there is the mid muffler and after that is the rear muffler.
the other thing that can be effecting my gas mileage is that I installed my winter tires 2 weeks ago. The tires are on steel (honda) rims that weigh a tonne!
So when i was taking the temp readings, it was from that secondary cat.
is it normal?
fab

 

I suspect your temp reading is not accurate. Watch real time fuel trims as you drive and report back.

 

Lex2k....
i have an obd scanner. Remind me...what's the best way to take the readings (ie: cruising at 100km/h....see what short-term and Long-term readings are)???