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Discussion Starter #1
uh oh......

intalled the 3in. DP w/out cat. on my 2000 9-3se and first bad news was that it would rub on the subframe brace...so i took that off

next...i just got the check engine light after about 45 miles driving it around....i am going to check the O2 sensors....and wires...but what could it be?.....the ecu reading it as something bad?......why....its so good!!!
 

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I agree with Adrian. I am willing to be that the lack of the cat is the cause of the CEL. Nothing you can do to turn off the light except to put a cat in it.
 

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I believe that US cars have two O2 sensors as oppposed to European cars that have one. I have a 3" downpipe on my GM900T without the Cat and have had no problems. I seem to remember reading that it is probably the second sensor that causes the CEL as presumably the emission reading is higher than it would be expecting?

Mike
 

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Originally posted by Eric (9-3 Hirsch):
[qb]I agree with Adrian.  I am willing to be that the lack of the cat is the cause of the CEL.  Nothing you can do to turn off the light except to put a cat in it. [/qb][/b]
Or remove the bulb.
 

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Discussion Starter #6
okay then nothing that serious...thats good...
i do plan on getting a cat it was just too much $ to buy all together....well see how it goes...thanks
 

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Here's a bit of a follow-up:

When OBD II was introduced it was decided that it would need in it's design a means for detecting the condition of the car's catalyst. So a second O2 sensor was added downstream. It measures the effectiveness in part by the concentration of gasses downstream, and in part by the delay in readings from upstream to downstream.

As the car cycles from rich to lean at idle (it does this for emmissions reasons as the catalyst needs O2 for certain reactions, and HC for others), the upstream O2 should receive the change in mixture a certain amount of time before the downstream. If this amount of time changes to near zero, as it will when the cat is no longer there, it will throw the Check Engine Light.

In some countries OBD II was not a requirement, and removing the catalyst will not cause a CEL. But it depends on how Saab programmed that individual model. Any Saab sold in the US (or car period), if properly functioning, SHOULD throw the CEL if the cat is removed.

Just keep looking around for a catalyst if it bugs ya. You can get a $50 one at Summit Racing ... hope it helps!

Cheers,
Dubbya
 

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I'm sure the California Emissions folks won't ignore the CEL. So you might fail without a cat... however, as everyone has already stated, its looking for the second lambda comparison.. Some try to cheat the system by installing one close to the turbo exit, and have another location created downline to install the second one. May or may not work, if the voltage comparisons are the same off the lambda.

I had the same problem when I put mine on, but I installed the race cat on mine. After locating a broken wire I replaced the O2 sensor for $75.00,
and my CEL went away....whew just intime for MD emissions inspection.

As far as your subframe support..., I hear MP Performance may have the solution around the dp.


DC
 

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I ran into same problem with the sub frame brace. Easy solution, find some 1/4" thick washers and install them between the brace and the sub-frame. my clearance is small but you can still fit a small coin in the space.
 

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Discussion Starter #11
i got the brace from MP....i think i will just sell it on ebay and make a stronger X-brace...

well see how that comes out...

the CEL does deffinitly bug...but ill try to reset it...and look for a cheap high flow cat..
 
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