I would start out with O2 sensor. It could be bad cat... but O2 sensor first.
Very depressed here ... I thought I would be in an out for this.
It's a `93 525i with 202k miles. It's not chipped. Just replaced the airfilter 2k ago. Will need to change the oil soon.
Here are the numbers:
Failed HC: Composite = 0.8 gpm
Reading = 2.37 gpm
Passed CO: Composite = 15.0 gpm
Reading = 14.1 gpm
CO2 = 386.8 gpm
NOx = 4.00 gpm
Could a cool cat be the cause? It's not suffering as far as fuel comsumption and idle is fine, except for once and a while, but that could be from the light weight flywheel ... when I clutch, it corrects the idle. I do not know when the O2 sensor has been changed, if ever.
Ideas, please.
Thanks,
Ken
I would start out with O2 sensor. It could be bad cat... but O2 sensor first.
You have high HC and CO too. Car's not burning all the fuel.
I'd give it a general tune up - plugs in particular - and strongly consider replacing your O2 sensor.
Be sure the cat is hot (no extended low speed idle) before the next test.
Jeff
Bellevue WA
90 535iM - not much stock remains. 3.7 liters, ported head, cammed, 3.73 diffy, M5 brakes, MAFed, yadda yadda yadda
86 Porsche 951 - Track Toy
It's what I thought and afraid of ... I had it checked out because the plugs are pretty new, and it runs strong with good fuel econ.Originally Posted by Jeff N.
The cat is dead
Any suggestions for a cat and I might as well do the headers ... any other parts?
Nuts!
Ken
Magnaflow cat...
man im glad we dont have to go thru this **** in oz. no emissions testing whats so ever.
Start with the oxy sensor. You can test it according to the Bentley book.
But if it has more than 60K miles, I would replace it.
http://www.autohausaz.com/catalog/lo...Token=49835494
I have 202k miles on it and had it tested ... it's no longer effective.Originally Posted by shogun
In my searching last night, I've seen people saying that OEM BMW cats are better than aftermarket.
Any thoughts?
Ken