Selespeed and catalyser issues

[SeleMatt]

Thanks for that Bazz and yes, I have cleaned the contact blocks, as stated earlier in the thread, with the worlds most expensive contact block cleaner, CRC. I've also cleaned the MAF sensor with their equally extortionate product for that job. Start up is producing a rather fuel vapoury exhaust at present. Economy is rather ordinary too. Still pulling like a teenager when up to full operating temperature though. Oil change tomorrow and I'm going to extract the plugs too, paying attention to plug No1 as the oil consumption is still a bit poor. May have an intake manifold issue.

[SeleMatt]

So.

Completed the self adaptation reset successfully. Drove up to the GC and back - a couple of hundred K's - and when about 5k's from home, back on goes the engine light. Catalyser PO420 and 430. Again. The engine light has consistently come on after a sustained period of highway running and not driving around locally stop/start. I can only assume the cats are cactus despite there being no obvious defect by visual inspection or any rattle.
Thoughts?

[bazzbazz]

Which sensors are the codes relating to? (Which Bank, Upper or lower)

[bazzbazz]

This is a copy of a response I have given to Citroënbender on a similar matter.

A lot of the times it is not the O2 sensor itself but connections. For example on the 147 TS one of the O2 sensor connectors is mounted on the side of the head between the head and gearbox at the front. Sometimes the  heat affects the connections and they lose contact. I solve that problem by using a pair of Forceps and twisting each pin in the grey plug 15 degrees so that it makes a tighter fit in the female pin.

The other cause of this is you have a leak in the exhaust. Can be caused by the following -

1/ O2 Sensor loose in its exhaust fitting
2/ Crack in any of the welds - this is usually caused by the exhaust taking a hit from large speed bump ect

Look for a black & whitish/grey powder flash from any of the welds where the exhaust gases have been leaking. If there is a crack/hole/leak it can be welded or sealed with Exhaust Putty.

[SeleMatt]

1) GROAN

2) When completing the first oil change after buying the car, I noticed a black carbon patch on the exhaust joint where the cat finishes; where it's welded to the engine pipe in front of the post cat sensor and so knew it was cracked. I had it welded up straight away.

3) After inspecting it this morning, I discovered the black patch has returned; obviously the weld has failed.

4) I think we can safely presume that the 4 new sensors fitted and purchased was pointless to the extent that the exhaust crack/leak/suck has been setting the engine light off.

5) GROAN

6) The exhaust shop tells me that this is not unusual and certainly not exclusively an 'Alfa' thing. Apparently you can weld an exhaust joint and sometimes it holds for ever...or 3 months....or you don't even get around the block. So they're going to weld it up again. If it doesn't work I'll have to get another manifold. I actually replaced all the exhaust hangers just after I bought the car because the back box was a little on the sag. I've sourced a brand new manifold for a grand which I believe is cheap. Hopefully the weld will hold this time... at least for a few months...
All a bit depressing.

[bazzbazz]

Just don't shoot the messenger. 

[SeleMatt]

One shouldn't ever shoot the messenger..thanks Bazz

And so onto the next job. The fitting up of the new gear position and gear engagement sensors.

Beyond the battery and tray removal, what else do I need to know? Can I remove anything else to improve access or is it pretty much by braille from there?

Any assistance appreciated.

[bazzbazz]

Gear Engagement Sensor is the one on top, straight forward.

The Gear Selection Sensor on the back is the tricky one, I do it myself by feel, but if you strain to look over the back of the actuator you can just see the RH screw and use that as a guide for the left one. Or you can position a mirror to do it.

Just make sure you use good quality torque tips, because if you round out the heads of the screws on the back sensor, you're gonna have to pull the actuator out.

[SeleMatt]

Thanks once again Bazz. Are the torx heads holding the sensors on the ones with the pin in the the centre or not?

Isn't the clutch sensor on the top of the actuator too...which is which?

I take it there's no improvement to access via removing the inner guard?

Thanks again.

[bazzbazz]

No pin.

Clutch Sensor is the one forward, closest to the radiator.

[poohbah]

Just thought I'd share - as a non-selespeed owner, I'm "proud" to say I had my very own genuine selespeed experience last week.

My 156 (V6 Q-auto) was in the workshop for belt change/service etc, and i was given a loan car to use overnight - a Series 1 Twin Spark 156 Sportwagon with selespeed.

Was quite good fun to punt about (you really can feel the weight difference of the 2.0 v the V6 and it was still pretty lively)

... until I drove the car to work next morning in peak hour traffic on the freeway.

I was pootling along happily in 2nd in stop-start traffic, when the car suddenly wouldn't rev above 1000rpm. Also wouldn't change gear, so tried to shift back into city mode, then managed to get back into 1st but it still wouldn't rev. It then went to neutral and wouldn't go into any gear at all.

So here I am stuck dead in the middle of the freeway, can't get off the road with cars piling up behind and honking/swearing at me, while I'm desperately thinking back to all your posts about dealing with a selespeed gone haywire.

Thought I'll try and reset, so turned ignition off, but couldn't get it to start again - for at least a (very looong) minute. At which point it fired up and all was good again.

While I did start laughing in the midst of it all - given it wasn't my car - I have to say I couldn't live with that sort of daily dread.

Felt like I had the sword of Damocles as a factory fitted option...

[bazzbazz]

From what you have described it sounds like it had nothing to do with the Selespeed. (In first/second gear and won't rev over 1000 rpm)

Sounds like you had a little "Target Fixation". 

If anything goes wrong with the Engine or Gearbox that may cause you to stop and get stuck in gear, thus immobile, the Selespeed Gearbox, if it can, will default to neutral to prevent you from being unable to move the car.

But then it could have been anything. (Crystal ball can't see that far)

My 156 Wagon is my work vehicle, and also a Selespeed. In 4 years of ownership the only thing that has let me down is a dead Crank Angle Sensor. The Selespeed has been flawless.

[poohbah]

Interesting - the injector warning light came on when it happened. When I handed it back I told the mechanics what had happened and they were going to check it out.

It was also making an awful rattle from under the floor at low revs, which they said was a buggered cat they hadn't bothered to replace.

I'd like to have a go in a TS with conventional 5sp and lowered suspension. They seem to wallow like a schooner in heavy seas on the factory set up, but the engine is brilliant.

[bazzbazz]

Well when that particular cat disintegrates it has a tendency to completely block the exhaust like a potato up the tail pipe, so no wonder that it wouldn't go over 1000 RPM. 

[poohbah]

All that aside - I've never had any of my Alfas with normal manual or Q-auto trannies suddenly prevent me from changing gear or rev without warning in the middle of the road. Except that pesky engine fire ....