MOT troubles

[johnco]

Hi all. I've recently bought a 2002 fd that is for all intents and purposeses completely standard. It went in for MOT last week and failed on 2 majors; no foglamp, and emissions.

The foglamp was easily fixed as some previous owner had installed a cheap aftermarket switch (which is now faulty) on the centre console which controlled a foglamp that was previously a reverse light.

Emissions is a bigger problem. The lambda reading is out of tolerance on idle and hydrocarbons okay, but vice versa between the 2500 - 3000 rpm required during emission testing. I took the car away and searched the forums for common emission problems, then bought a set of leading / trailing plugs and a new lambda sensor. I will also check that the air pump is working, will check tps is within calibration, and have already taken the cat off for a look to see if it's nackered.

I've come to here for 2 main questions.
1) Is the air pump test as simple as I think, ie just pull off a hose and check that air is blowing?
2) While taking off the cat I found that the air feed to the cat has a home-made blanking plate sandwiched between the bolting flanges at the cat connection on the left hand side of the cat. There also appears to be another blanking plate on the right hand side of the cat. From viewing images of catalytic converters for fd's online, it looks like the rh blanking might be an exit of some sort? Why would the air feed have been blanked? Is it a performance gain? And where should the connection on the rh side go from the cat?

I'd appreciate any knowlegde on this, I've been scratching my head this morning!

 

[Jit]

A stock 2002 cat should only have the airfeed take off from memory. Sounds like you might have an earlier cat fitted that has a take off for a cat heat sensor (96- cars didn’t have this). Could be a variety of reasons why it’s been changed though and the presence of the heat sensor take off won’t be affecting your emissions.
If the air feed from the airpump to the cat has been blocked off at the cat end, this won’t be helping at all in terms of emissions and you should re connect it.
Given your location though, I might be tempted to take it to an MOT garage that is sympathetic to the emissions needs of an RX7. There is one not too far from you

 

[Ceylon]

Yep, as Jit says, you have an early CAT. The airpumps are generally pretty hardy.

Did the test centre put the car details in properly? You get a more lenient test if you select the correct car for the FD.

 

[johnco]

Thanks chaps, I see exactly what you mean with the early cat having a temp sensor from looking at the diagrams on nengun.com.

Not sure if they put in the details correctly for the MOT, I'm going to change the plugs and lambda sensor tonight as well as reconnecting the air pump. I can take it back over to the MOT centre tomorrow because it's still within the 10 day retest time (until Sat) and see if it passes with just these changes. If it fails again I'll book into a more 'friendly' MOT centre.

Since I've bought the car I have noticed that it absolutely stinks the place out with a rich fuel smell when it runs. I appreciate they probably smell a bit more than a piston engined car but this is another level. It even stinks inside my house! I was hoping to get that under control a bit, for the missus' sake.

Will update here tomorrow and see if the changes make much difference

 

[welshkid]

If it smells that bad on a stock car, think you may have more problems than just a blocked air feed to the air pump.
Not sure if you can on the 2002 ecu, but worth trying to pull the codes see if anything else is flagged.
As others have said, when you take it for re-test, have a word with a tester and make sure they are doing a vehicle specific emissions test as it changes the RPM etc that they test at (to suit the air pump operation conditions)

 

[JoeLanger]

If HC is OK then I would say just the air pump was causing the issues. Soon find out on a re test.

Most would take it to places that are familiar with an FDs requirements

 

[cib24]

If air isn't getting to the cat with the air pump line then the car will smell like fuel. The air does a lot to clean up the exhaust and help the cat work. Also, if that isn't working because it's blocked off you'll be killing your ceramic cat core in no time.

 

[johnco]

I stripped the cat out last night and gave it a shake. It had a rattle and some of the core fell out so I managed to pick up a BM catalysts cat and get it on the car today and got the air pump reconnected. Changed the plugs, lambda sensor, and air filter as well aaannnnnddddd.......

Passed MOT!!

Thanks for the hints about telling the tester to make sure to enter the vehicle range. It gave quite a bit more allowance on the lambda reading.
The smell has reduced significantly now and the CO & HC are under control

 

[Jit]

Nice one! Hopefully that cat lasts the distance! Aftermarket cats can be known to clog up/break apart given the amount of heat produced by a rotary.

 

[JoeLanger]

congratulations, you have a unicorn FD

 

[noyzboy]

Good result

 

[tread7]

Did the cat last or block up at all? I'm in the exact same scenario as you and debating reconnecting the air pump line to the new cat or blocking off the new cat. Thanks