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I have a 1997 BMW Z3 6cyl that keeps burning up catalytic converters. The check engine lite comes on and gives me 2 codes (F5- secondary air system flow too low cyl. 1-3)(E9- cat. efficiency below threshold 1-3).Do you have any ideas?
Thank's Fred

Submitted: 178 days and 13 hours ago.

Category: BMW

Value: $40

Status: CLOSED

1997 BMW z3 6cyl

Already Tried:
Plugs,new cat.,looked for vaccum leaks,replaced front and rear o2 sensors

Posted by Sam 178 days and 13 hours ago.

Info Request

Hello and welcome to Just Answer.

It sounds like you have a few issues going on here.

Can I get the last 7 digits of your VIN number?

Do you have the "P-codes" or OBD fault codes?

What kind of catalyetic converter did you install?

178 days and 13 hours ago.

Reply

vin LC05696
Codes came from my Peak code reader
After market bolt in cat. if you need the exact make i'll have to look it up

Posted by Sam 178 days and 13 hours ago.

Answer

The aftermarket cat is the reason for the faults returning. Most aftermarket cats cannot flow enough to please the DME.

The secondary air is nost likely a broken vacuum feed hose to the arresting valve or a bad valve.

178 days and 13 hours ago.

Reply

Sam-
Thank's for the info but the original cat burned up too so I question the after market cat being the problem . Could it be the engine is too lean or too rich?The insides of the original cat and after market cat turn to dust.

Posted by Sam 178 days and 13 hours ago.

Info Request

You would have to run the vehicle so lean to create the kind of heat to destroy the cat, the car wouldn't run.

How long did the aftermarket cat last? How about the original one?

178 days and 13 hours ago.

Reply

The car has a total of 67800 miles the first cat died at around 48000 miles the second at around 20000 miles

Posted by Sam 178 days and 12 hours ago.

Answer

The catalyetic converter problem is pretty common. I have only seen a few aftermarket catalyetic converters that will last in a BMW. They don't flow as well as the factory cats so they start to plug up and get super hot, that's what destroys the insides of them.

178 days and 12 hours ago.

Reply

Should a factory cat last longer than 48000 miles?My local BMW dealer wants $2600.00 for a factory rebuild, seems a little overboard.

Accepted Answer

I have never seen a factory cat fail with that few miles. That is definately a rarity. If it was me, I would find a used cat. If you can find one, It should anly cost $100-$200.

Accepts:
Expert:	Sam
Pos. Feedback:	100.0 %
Answered:	5/27/2009

BMW Master technician

BMW S.T.E.P. graduate, 10 years BMW dealership experience

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Question

I have a 1997 BMW Z3 6cyl that keeps burning up catalytic converters. The check engine lite comes on and gives me 2 codes (F5- secondary air system flow too low cyl. 1-3)(E9- cat. efficiency below threshold 1-3).Do you have any ideas?
Thank's Fred

Optional Information

1997 BMW z3 6cyl

Already Tried:
Plugs,new cat.,looked for vaccum leaks,replaced front and rear o2 sensors

Info Request

Hello and welcome to Just Answer.

It sounds like you have a few issues going on here.

Can I get the last 7 digits of your VIN number?

Do you have the "P-codes" or OBD fault codes?

What kind of catalyetic converter did you install?

Reply

vin LC05696
Codes came from my Peak code reader
After market bolt in cat. if you need the exact make i'll have to look it up

Answer

The aftermarket cat is the reason for the faults returning. Most aftermarket cats cannot flow enough to please the DME.

The secondary air is nost likely a broken vacuum feed hose to the arresting valve or a bad valve.

Reply

Sam-
Thank's for the info but the original cat burned up too so I question the after market cat being the problem . Could it be the engine is too lean or too rich?The insides of the original cat and after market cat turn to dust.

Info Request

You would have to run the vehicle so lean to create the kind of heat to destroy the cat, the car wouldn't run.

How long did the aftermarket cat last? How about the original one?

Reply

The car has a total of 67800 miles the first cat died at around 48000 miles the second at around 20000 miles

Answer

The catalyetic converter problem is pretty common. I have only seen a few aftermarket catalyetic converters that will last in a BMW. They don't flow as well as the factory cats so they start to plug up and get super hot, that's what destroys the insides of them.

Reply

Should a factory cat last longer than 48000 miles?My local BMW dealer wants $2600.00 for a factory rebuild, seems a little overboard.

Accepted Answer

I have never seen a factory cat fail with that few miles. That is definately a rarity. If it was me, I would find a used cat. If you can find one, It should anly cost $100-$200.

BMW

Have your own BMW question?

Related Bmw Topics:

Question

I have a 1997 BMW Z3 6cyl that keeps burning up catalytic converters. The check engine lite comes on and gives me 2 codes (F5- secondary air system flow too low cyl. 1-3)(E9- cat. efficiency below threshold 1-3).Do you have any ideas? Thank's Fred

Optional Information

1997 BMW z3 6cyl Already Tried: Plugs,new cat.,looked for vaccum leaks,replaced front and rear o2 sensors

Info Request

Hello and welcome to Just Answer. It sounds like you have a few issues going on here. Can I get the last 7 digits of your VIN number? Do you have the "P-codes" or OBD fault codes? What kind of catalyetic converter did you install?

Reply

vin LC05696Codes came from my Peak code readerAfter market bolt in cat. if you need the exact make i'll have to look it up

Answer

The aftermarket cat is the reason for the faults returning. Most aftermarket cats cannot flow enough to please the DME. The secondary air is nost likely a broken vacuum feed hose to the arresting valve or a bad valve.

Reply

Sam-Thank's for the info but the original cat burned up too so I question the after market cat being the problem . Could it be the engine is too lean or too rich?The insides of the original cat and after market cat turn to dust.

Info Request

You would have to run the vehicle so lean to create the kind of heat to destroy the cat, the car wouldn't run. How long did the aftermarket cat last? How about the original one?

Reply

The car has a total of 67800 miles the first cat died at around 48000 miles the second at around 20000 miles

Answer

The catalyetic converter problem is pretty common. I have only seen a few aftermarket catalyetic converters that will last in a BMW. They don't flow as well as the factory cats so they start to plug up and get super hot, that's what destroys the insides of them.

Reply

Should a factory cat last longer than 48000 miles?My local BMW dealer wants $2600.00 for a factory rebuild, seems a little overboard.

Accepted Answer

I have never seen a factory cat fail with that few miles. That is definately a rarity. If it was me, I would find a used cat. If you can find one, It should anly cost $100-$200.

Related BMW Questions

I have a 1997 BMW Z3 6cyl that keeps burning up catalytic converters. The check engine lite comes on and gives me 2 codes (F5- secondary air system flow too low cyl. 1-3)(E9- cat. efficiency below threshold 1-3).Do you have any ideas?
Thank's Fred

1997 BMW z3 6cyl

Already Tried:
Plugs,new cat.,looked for vaccum leaks,replaced front and rear o2 sensors

Hello and welcome to Just Answer.

It sounds like you have a few issues going on here.

Can I get the last 7 digits of your VIN number?

Do you have the "P-codes" or OBD fault codes?

What kind of catalyetic converter did you install?

vin LC05696
Codes came from my Peak code reader
After market bolt in cat. if you need the exact make i'll have to look it up

The aftermarket cat is the reason for the faults returning. Most aftermarket cats cannot flow enough to please the DME.

The secondary air is nost likely a broken vacuum feed hose to the arresting valve or a bad valve.

Sam-
Thank's for the info but the original cat burned up too so I question the after market cat being the problem . Could it be the engine is too lean or too rich?The insides of the original cat and after market cat turn to dust.

You would have to run the vehicle so lean to create the kind of heat to destroy the cat, the car wouldn't run.

How long did the aftermarket cat last? How about the original one?