failed smog please help
 

hey guys failed California smog. the cars has new plugs, o2 sensor, vacuum lines the cats about 4 years old. any help would be appreciated here are the numbers.

1988 944


15mph
%co2- 12.7
%o2- 2.3
hc max-83 gp-293 meas- 180
co max-.75 gp-2.25 meas-.60
no max-575 gp-2002 meas-2822

25 mph
%co2-13.0
%02-1.9
hc max-65 gp243 meas-58
co max-.63 gp-2.13 meas-.60
no max-738 gp-1802 meas-1410

Im thinking the AFM is way out of adj.


Thanks
Matt

High NOx is usually a result of the car running excessively lean. The most common reason for this are vacuum leaks. Second is just a bad cat. Make sure you get the cat very hot before taking the test, drive the car on the highway for a little while and see if you can 'roll right in' off the street for the test.. dont shut the car off or let it cool off.

Yeah that was after a hour on the fwy and a five min wait for the paperwork then test

Could also be the O2 sensor making it run lean

Could be also the DME temp sensor on the block is defective.

Test both...

okay i tested the DME temp sensor and it seems out of spec here are the numbers

@55-57 deg 2.90 k-ohms spec is 3.3
@176 deg 264 ohms spec is 280-360

so lower than specs means leaner but would it be that much of a difference?

The DME temp sensor is not that much money - replace it. It has probably been bad for quite some time now. If you run a 944 motor for to long with to lean of fuel supply you take a good chance of burning the valves.

The fan of CAPS LOCK has passed his smog. He cheated but he passed.