My Car (1996 and covered 28,000 miles) has just failed it's Emissions test with the following results.......

ENGINE SPEED (2350/2650 RPM)

CO LEVEL: 4.45% (MAX 0.30%) FAIL

HC LEVEL: 126 PPM (MAX 200) PASS

LAMBDA: 0.87 (0.97/1.60) FAIL

Just wanted to ask if anyone can shed light on why I'm getting these results.

The engines running fine and smooth, there are no noticible problems.

As I do most of the servicing myself, is there something I should have changed in the past year?

The Mazda garage thinks it's a failed/failing CAT while an RX7 specialist thinks that one of the sensors in the emission system is malfunctioning.

Thank You!

 

When I failed emissions I found out later that my EGR valve was broken.

 

Interesting how the allowed (max) readings are so different here in Denmark. I would have passed in the UK.
your reading my reading
CO - 4.45% (max 0.30%) CO - 0.015
HC - 126 ppm (max 200) HC - 119
Lambda - 0.87 (max 0.97-1.60) Lambda -1.158
(Max - 0.97 -1.03)

I failed here 2 weeks ago. He wanted to give me another run, but my exhaust tip burned a hole thru their
ventilation hose attached to the sniffer. Instead he passed me. Said he would give me the benefit of doubt!
I said "sorry for the hose and thanks". It's nice when the emissions tester likes the car. We have only 8 in the country.

Andrew - the four easy things to do are:
change oil
change spark plugs
disconnect and plug the catch tank
and make sure your main cat is good and hot

 

Check this thread:
https://www.rx7club.com/forum/showth...threadid=89070
It is for CALIFORNIA emissions testing but the Info may help you also.

 

Thanks for all the info, it's all very useful.

It's worth adding that the EGR Valve isn't fitted to European Spec Cars.

Although the car is booked into a Specialist to be looked at I may try changing the plugs to see if it makes any difference (they were due to be changed anyway).

I may try changing the 02 Sensor as well (depends on how expensive it is).