Catalytic converter issue--I think
11-01-15, 10:28 AM
#1
Rookie
Thread Starter
Join Date: Aug 2015
Location: North Carolina
Posts: 74
Likes: 0
Received 0 Likes
on
0 Posts
Catalytic converter issue--I think
My '95 LS400 had had an exhaust leak for months, and I finally got around to patching it. I was never 100pct sure where it was, so I patched a number of suspect sites. Moved it around in the garage, got under it to do something else and...the plastic shield over the brake lines appears to have melted and drooped. It wasn't like that before. Doing it just south of the passenger side cat.
My theory is that it's plugged and that when I patched the leak, the exhaust has nowhere to go on that side. The driver's side doesn't have the same problem. Car doesn't idle as smoothly as wife's Sienna, but sounds driveable.
I have a Centech laser thermometer from Harbor Freight and it's giving me low 400s on the outlet end and high 100s-low 200s on the inlet. The other cat gives me about the same on the inlet but no higher than 350 on the outlet. This is after 5min of idling, and the rpms have dropped to around 500. Very, very low. This is the first time I've used a thermometer like this so I don't know if I'm doing it right.
A little background; when I bought this car off Craigslist, it had an awful idle. Almost wouldn't run. I fixed a vacuum leak and a plugged PCV valve, and it ran great--except for that exhaust leak. I've put about 800 miles on it with the CEL on. The codes are for both cats, but I always chalked that up to leaky exhaust.
Also, the melting brake line weather shield wasn't melting anymore during this test. Maybe I didn't run it enough, but it wasn't much less than when I moved it in the garage.
So...does it sound like my cats are plugged/fried? Should I consider replacing the O2 sensors? In the interest of domestic bliss, I'm trying to go easy on the budget.
My theory is that it's plugged and that when I patched the leak, the exhaust has nowhere to go on that side. The driver's side doesn't have the same problem. Car doesn't idle as smoothly as wife's Sienna, but sounds driveable.
I have a Centech laser thermometer from Harbor Freight and it's giving me low 400s on the outlet end and high 100s-low 200s on the inlet. The other cat gives me about the same on the inlet but no higher than 350 on the outlet. This is after 5min of idling, and the rpms have dropped to around 500. Very, very low. This is the first time I've used a thermometer like this so I don't know if I'm doing it right.
A little background; when I bought this car off Craigslist, it had an awful idle. Almost wouldn't run. I fixed a vacuum leak and a plugged PCV valve, and it ran great--except for that exhaust leak. I've put about 800 miles on it with the CEL on. The codes are for both cats, but I always chalked that up to leaky exhaust.
Also, the melting brake line weather shield wasn't melting anymore during this test. Maybe I didn't run it enough, but it wasn't much less than when I moved it in the garage.
So...does it sound like my cats are plugged/fried? Should I consider replacing the O2 sensors? In the interest of domestic bliss, I'm trying to go easy on the budget.
Thread
Thread Starter
Forum
Replies
Last Post