Question on Laser / IR Thermometer

[Spammy_H]

Does anybody have experience with one of these? Do the cheap ones on eBay work well enough to measure the temperature differences in the tailpipe before and after the catalytic converter, or do I need one that costs some real money to do that?

My semi-repaired Dodge Intrepid (many thanks to those who helped me identify the crankshaft position sensor as the culprit of non-starting) is throwing a P-code that indicates either a bad O2 sensor, or a bad catalytic converter.

Since the 2 downstream O2 sensors run about $70, I was thinking about investing in a cheap laser/IR thermometer to try to diagnose if my cat's bad, or if it is the 2 O2 sensors downstream from the cat.

Here's one for about $23 shipping included (actually, it's mostly shipping):

Infrared IR Laser Non-Contact Digital Thermometer - eBay (item 280556210448 end time Sep-01-10 12:58:13 PDT)

If this isn't the route, can you recommend one that is "good enough" for the job w/o breaking the bank?

Thanks again.

[obieone]

I work in the HVAC trade, and NO, I wouldn't buy that. I see no brand name on the unit, and none listed in the description.
Some brands to look for: Fluke, Raytek, UEi, Extech, etc.

[titaniumskull]

Originally Posted by obieone

I work in the HVAC trade, and NO, I wouldn't buy that. I see no brand name on the unit, and none listed in the description.
Some brands to look for: Fluke, Raytek, UEi, Extech, etc.

I concur. I work Heavy commercial trucks and trailers as well as Carrier and Thermo King and I will stick with the one I got from Snap On. If its to darn cheap then it will not be consistent and too many variables

[VDubbinMI]

Seeing as how your only using this to pinpoint a failing catalytic converter and not something your going to make a living using everyday I would say that it should be fine for what you're doing. It states that it has a 2% accuracy or within a range of 2*C. That should be more than sufficient for the job. Just keep in mind that sitting at idle or holding the engine at 2500 rpm might not create enough load on the engine to show an accurate result.


Edit: If you want to test the 02 sensors you can use a multimeter and probe the connector for the 02 sensor. You should have the meter set to mV and watch to see if it switches from low to high, back and forth again.

Do you know the actual P code? It could be a fault for the 02 sensor heater circuit also depending on what the error code is.