Code numbers from scanning

Test pipes will most definitely generate codes, possibly more than before.

If the pump is not running when the engine is running, then it could be a relay or wiring problem. As I said before, I don't know how the ECU is detecting the 2ndary air failure, so it could be anything in that system causing the code, from hoses to relays.

Anyway, here's a diagram I threw together earlier...

5.2 Engine Ignition Diagram

The diagram doesn't show relay socket numbers, though. The relay base sockets hooked up to the pump and to the solenoid valve should be 87 and 87a (I just don't know which goes to which). The relay is energised when the ignition key is in ON and the Motronics ECU commands the pump on (The ECU provides an earth). There should be enough information in the rest of the diagram to figure out which socket on the solenoid valve's 2-pin plug goes to the relay (the other goes to earth).

If you need help reading the diagram, let me know.

 

I had to use 90 degree bend spacers in the post cat 02 sensors with mini high flow cats. No more codes. all fixed so far after 4 drives

 

87 and 87a are the outputs of relay "L" which exit the relay panel on plug H (pins 4&5). The black/red and red/black wires on pins 4&5 go to the solenoid valve and pump respectively. I don't know if you're familiar with the relay panel, but the plugs are behind the panel and not easy to get to (This is why you'll have to use the relay base sockets for your wiring checks.)

 

While you're checking the wiring to the solenoid valve (the one with the blue plug), check to see if the resistance of the solenoid coil is around 55ohms. Of course, make sure the tubing coming from the valve with the blue plug goes to secondary air cut off valve (inboard of the filter), not to the exhaust bypass valve.

According to the workshop manual, the ECU should open the secondary air valve and run the pumps in the follow circumstances:
During the cat warmup period
When the O2 sensors aren't up to operating temperature
When the coolant temperature is too low (between -7C and 50C on USA cars)

As Grant says, don't get too carried away with these checks. As he suggested, your cats could be causing all these messages (depending on the fault logic for the secondary air system).

(EDIT) If you can determine without a doubt that, say, pin 87 of the relay goes to the solenoid valve and pin 87a goes to the pump, I'll add that detail to my diagram to help folks in the future.

 

There is a known amp draw issue with the pump that blows fuses and in my case melted the connector at the pump.

Pull the connector off the pump and inspect the contacts.

 

This is how they do it.

When the engine is up to operating temperature, the ECU turns on the secondary air pump to induce a lean running condition. If it does not see that from the O2 sensor precat, then it throws the CEL secondary airpump circuit not working. And it also does not allow the monitor to be 'ready" and you fail the smog test.

While these two CEL codes seem unrelated, I would fix the cat efficiency code first and then see if the secondary air code also goes away.

Possible secondary air culprits are many:

1. Bad Ecu, or bad ECU wiring
2. Bad air solenoid
3. Bad vacuum can
4. Broken hose(s)
5. Bad pump

 

Probably not, but a mini-cat and steel wool would take care of that low efficiency error.

 

Right now you don't have any knowledge what is causing the CAT code. If the element is breaking up - that's bad. You really need to find the root cause of the problem. If you want to remove the cats, gut them, or install test pipes and then fake the system out, that's a separate issue.

Broken pieces of the CAT ceramic element left inside is dangerous. It's time to open them up and have a visual inspection.




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If they are gutted that certainly is the cause for the issue. I'd be suprised that Brian would let a car leave his shop with a CEL. Guessing more to the story.

For $1500 and a couple hours labor you could install hi flow CAT's. Your problems would be gone and the people in cars behind you could breathe freely without watering eyes.

 

Mitchell, this is completely opposite to what is written in Workshop manual 1, page C44. Something lost in Italian to English translation?

 

Mitch must have had a type O. The secondary air injection system is for cold cats, not hot. I'm certain Mitch knows this, VERY certain.

 

Maybe it does both. I did ni think so but what Mitchell said does make sense.

If the OP could clarify, you said that Brian said cats were weak, niw you said they were cleaned out, as Dave said if they are cleaned out so they are now empty inside this is your problem. If you want to leave thm like that and not throw a cel you need to trick them as Dave also said.
Again I would not bother with all the other stuff until you fix the cats. Your engine needs one or the other

 

Hold your horses.

When you reset the CEL, the computer has to start from scratch and go through its self test of all OBD2 emission monitors. One of the monitors is the operation of the secondary air injection system. The ECU tests that system by warming up the engine to operating temperature and then injecting the extra air to see if the car runs leans or not. If not, it throws a code and you fail your OBD2 test.

When all the monitors are known to be working, then normal operation is for the air injection system to come on only at start up to help burn the excess rich fuel in the system at cold start.

So, it does both at certain times.

 

Thanks for the clarification, Mitchell.. Makes more sense now.

Cheers

 

That page makes my eyes hurt... But looks like a decent product!

 

I'm glad my horses are held

Yes - that's correct.


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I am happy I have your trust.