cat deleted but engine light on

[zero 1162]

So I did a cat delete on my n46 engine a while back, and it threw a cat code.

It didn't bother me until today it dawned on me that the ecu is probably over fueling to compensate for what it thinks is a dead cat.

How do I fool the computer? Can I simply unplug the plug to the post cat sensor, or earth the plug, or join the wires together?

The sensor is just behind the cat (1) in the following pic;

http://realoem.com/bmw/showparts.do?model=EX52&mospid=47663&btnr=18_0452&hg=18&fg=10

Any help would be appreciated.

[B.M.W Ltd 950]

What was the reason for deleting the cat ?

[westy 614]

It kept pissing in the corner....

[zero 1162]

What was the reason for deleting the cat ?

It was clogged, so I cut it out, removed the internals, and welded it back in.

It gave me slightly better revs.

[B.M.W Ltd 950]

It was probably clogged with oil from your valve stem seal problem.... have you had this repair done yet ? I don't know of a cat delete program or "code out" option for an N46 and they also don't like after market cats...been there

[HaNs 226]

I can delete the codes in the ECU so they won't come back, other way is a mini cat extension on the post cat sensor (call red line or check trademe)

[zero 1162]

It was probably clogged with oil from your valve stem seal problem.... have you had this repair done yet ? I don't know of a cat delete program or "code out" option for an N46 and they also don't like after market cats...been there

No, I haven't had the valve seals done yet, but I've been saving up so I can get it done in the next 6 months.

[zero 1162]

I can delete the codes in the ECU so they won't come back, other way is a mini cat extension on the post cat sensor (call red line or check trademe)

Yes after doing more research, extending out the sensor was what I was thinking might be my best bet.

I was thinking of using the spark plug defouler mod: http://www.amazon.com/Dorman-42009-Spark-Plug-Non-Fouler/dp/B000CO91FY

Looks like redline have something similar: http://www.trademe.co.nz/motors/car-parts-accessories/performance/exhaust/auction-862985203.htm

Which one do I need though, as they also have this: http://www.trademe.co.nz/motors/car-parts-accessories/performance/exhaust/auction-863460513.htm

[HaNs 226]

Id go the mini cat, i have no idea what codes you have as you havent posted any?

[zero 1162]

The code I have is the one below;

http://upkeep.us/OBDII/OBD2/BMW/piart.php?art=2907

It says power steering control module, but thats using a cheap adapter and the torque app on my phone.

When I saw Glenn at BMW ltd a while ago he scanned it with his professional scanner and it brought up a cat code, but I cant remember which one.

I bought a cat sensor extension from redline and fitted it last night, but before I could do anything else I noticed a water leak under the car.

Turns out the water pump is leaking, and is the original one from 2004 (130kms), so I will be replacing that today before I go for a drive.

This is the sensor extension I bought;

http://www.trademe.co.nz/motors/car-parts-accessories/performance/exhaust/auction-862985203.htm

I figured for $25 it was worth a try.

[zero 1162]

What a mission this has turned out to be.

The waterpump is tricky on the N42/N46 to get out as its connected to the back of the power steering pump and there is very little space to move.

And I couldn't get a new water pump until yesterday because of the Easter weekend.

Then I couldn't get the connector out of the old waterpump to put in the new one - its number 7 on this link;

http://realoem.com/bmw/showparts.do?model=EX52&mospid=47663&btnr=11_3192&hg=11&fg=35

In the end I had to carefully cut up the old waterpump to get the aluminium connector out.

In doing so I damaged the seals on the connector so went and got new ones which took a while as the first two places didn't have any in stock (repco, team mcmillan BMW).

Anyways, I got it in today and went for a test drive, and no leaks.

Back to the cat codes.

I have deleted the old cat codes, and over the next few days of driving we will see if it reappears.

[zero 1162]

Done over 100kms of driving and the check engine light hasn't come on again, so fingers crossed.

[polley 916]

The water pump is run off the back of the power steering pump? yuck.

[zero 1162]

The water pump is run off the back of the power steering pump? yuck.

Yea it was a pain to get off.

I had to use a different combinations of adapters, extensions and universals for each of the four torx bolts on the power steering pump.

Skinned a few knuckles lol.

[zero 1162]

Well, its been a while and no check engine lights or codes thrown.

The $25 fix did the trick.

Thanks to all for the advice.

[allan 295]

Only if a bit late but have the whole set up sitting in the back room from when I did the engine swap water pump, thermostat, steering pump. As you have discovered a right pita to get at and even separate when in place.

[B.M.W Ltd 950]

You don't separate them in place. You take them off together and separate on the bench