In CA(I know). 2006 Nissan Xterra 2WD Auto Trans 137,500+ miles. Check engine light on. No other issues noted. FIXD unit states no issues found. Two mechanics state I need a new catalytic converter. Should I see a 3rd mechanic or just get a new catalytic converter. New car is out of the question. Prices for new and used are ridiculous!.
CEL is on, but what are the codes?
Did any mechanics do a back pressure test on your exhaust to confirm that you need a new catalytic converter? If so, how many psi is the pressure?
You should ask them.
Thanks for the responses. I'm not code savvy, or auto savvy. But, for some odd reason my check engine light went off. So I ran my car on the freeway for 60 miles(youtube said this might work). Drove straight to a Star Smog test station. I said nothing about the previous mechanics. They tested my car right away. About 15 minutes later I drove out with a passed smog test. Go figure.(???) Saved $1500 anyway. And my FIXD unit still states no issues.
Do you know the code from the check engine light?
Generally, a catalytic converter problem will trip a P0420 code. P0420 usually means a problem with either the 02 sensor or the catalytic converter. If you don't have a P0420, you shouldn't have a problem with the cat or the 02 sensor.
I'm not familiar with the FIXD app (unlike Blue Driver and MX Plus, which I am familiar with. I'm assuming that there's enhanced diagnostics/mode6/live data modes).
I don't know if or what modes you've run, but run them multiple times, to ensure that the readings are at least consistent.
NOW, it may be that your converter is running ever so slightly below maximal efficiency. Scotty claims that lacquer thinner might help, in one video, and even soap and water, in another. Just go to the FAQs on this site, find the link to the search engine of Scotty's videos, type in "catalytic converter" and check those videos out.
And, by way of triangulating the condition of the cat, if a friend has a different scan tools (Blue Driver, MX Plus, Innova, etc.), ask to run their scan tool on your car. All testing devices have some degree of Type I (false positive) and Type II (false negative) errors. It wouldn't hurt to confirm or disconfirm what FIXD has produced, in terms of data, with another scan tool.
The only other thing I can think of is that the cat is rattling (broken). It's a honeycomb-type of arrangement, inside the housing. If it breaks and then rattles, well, that's that.
Good Luck.
