Rusty_ratchet
Member
- Joined
- Apr 14, 2015
- Location
- Southwest
1985 Volvo 240
I took my car in for emissions testing and failed.
The results of the test are below:
I tested the O2 sensor using a labscope. The voltage was alternating between approx 0V and 1V. I also believe it is fast enough.
I checked for vacuum leaks using a smoker. I found a small leak at one of the air intake hose nipples. It was pretty small, but a leak never the less. It is an aftermarket hose and the nipple was deformed into a sort of "D" shape. I still have the original and put it back on. No leaks now, and I'm skeptical that the previous hose had enough of a leak to be a problem.
I measured the temp of the pipe just before and after the catalytic converter. It is 490 F at the front and 550 F at the back. Should the temp be lower at the front?
I pulled the spark plugs and some photos are shown below (1 on the far left, 4 on the far right):
The plugs have 22k miles on them. They were gapped to 0.028" when I installed them and are now 0.032" except for the cylinder 4 plug that is 0.033". This is more wear than I would have expected. I would have thought that it would be closer to 30k miles before they reached their limit. I am using Volvo plugs.
All the plugs look dry, except for the cylinder 4 plug:
There is an exhaust leak at the header pipe. This is after the O2 sensor. Does it make a difference in smog since it is after the O2 sensor?
I took my car in for emissions testing and failed.
The results of the test are below:
I tested the O2 sensor using a labscope. The voltage was alternating between approx 0V and 1V. I also believe it is fast enough.
I checked for vacuum leaks using a smoker. I found a small leak at one of the air intake hose nipples. It was pretty small, but a leak never the less. It is an aftermarket hose and the nipple was deformed into a sort of "D" shape. I still have the original and put it back on. No leaks now, and I'm skeptical that the previous hose had enough of a leak to be a problem.
I measured the temp of the pipe just before and after the catalytic converter. It is 490 F at the front and 550 F at the back. Should the temp be lower at the front?
I pulled the spark plugs and some photos are shown below (1 on the far left, 4 on the far right):
The plugs have 22k miles on them. They were gapped to 0.028" when I installed them and are now 0.032" except for the cylinder 4 plug that is 0.033". This is more wear than I would have expected. I would have thought that it would be closer to 30k miles before they reached their limit. I am using Volvo plugs.
All the plugs look dry, except for the cylinder 4 plug:
There is an exhaust leak at the header pipe. This is after the O2 sensor. Does it make a difference in smog since it is after the O2 sensor?
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