Catalytic Converter/check Engine Light/flexi Pipe

[dan-ny]

Folks,

I am posting this after reading a bunch of postings on the forums.......not yet discovered the answer to my problems with 1999 Rx300 (97K Miles).

It started with a Check Engine Sign.....used the Snap-In tool....it tells me bad O2 sensors. To be sure, I replaced all three o2 sensors.....damage was $900.......the check engine sign comes back after 25 miles of driving.

Next I stop by the dealership.....they print out a laundry list of things mostly unrelated (ex. brakes).....but tells me to replace Catalytic Converter, Thermostat, Gaskets and a 'flexi' pipe in the front of the CAT. All this adding upto much more then the value of the vehicle.

So here are the questions for the experts out there....

1) Has anyone seen anythign similar?

2) Any recommendations on changing the CAT with an OEM product (ex. Eastern)?

3) Is there a easy way out? I just want to get rid of the light and trade-in the vehicle.

Any comments and suggestions are welcomed.

[SKperformance]

From the other posts of the same it seems to be your egr pipe may be leaking connected to the exhaust from a crack.

Otherwise you MAF could use cleaning.

[wwest]

Folks,

I am posting this after reading a bunch of postings on the forums.......not yet discovered the answer to my problems with 1999 Rx300 (97K Miles).

It started with a Check Engine Sign.....used the Snap-In tool....it tells me bad O2 sensors. To be sure, I replaced all three o2 sensors.....damage was $900.......the check engine sign comes back after 25 miles of driving.

Next I stop by the dealership.....they print out a laundry list of things mostly unrelated (ex. brakes).....but tells me to replace Catalytic Converter, Thermostat, Gaskets and a 'flexi' pipe in the front of the CAT. All this adding upto much more then the value of the vehicle.

So here are the questions for the experts out there....

1) Has anyone seen anythign similar?

2) Any recommendations on changing the CAT with an OEM product (ex. Eastern)?

3) Is there a easy way out? I just want to get rid of the light and trade-in the vehicle.

Any comments and suggestions are welcomed.

Actual code(s) are..??

[lenore]

If the flex pipe is cracked way open, the air leak may be causing a bad o2 reading at the cat. I would go to a muffler shop and get that flex piece repaired first. around $100 to do so, but a lot cheaper than the dealership.

[dan-ny]

Thanks for everyone's response and feedback. Here's the latest scoop......

After changing all the O2 sensors....

1) I had Meineke replace the Flxe pipe......a 180 buck hole.....in holiday season ! :-(

2) Removed the EFI fuse to rest the light

The light stayed off for 5 miles.....and you guessed it.........it came back. So I went to Autozone to get the latest reading. These are the two codes:

P0330 - Knock sensor condition

- a malfunction exists in electrical circuit for knock sensor2 (Bank2) (bank 1 identifies the location of cylinder #1, while bank2 identifies the cylinders on the opposite side)

P0171 - Fuel trim bank one condition

- the fuel system for bank 1 was too lean (Bank 1 identifies the location of cylinder #1, while bank2 identifies the cylinders on the opposite side)

Thoughts? Suggestions? I am now confused......and lost.

Thanks in advance.

[lenore]

You could try this to clean the MAF sensor, It is cheap, easy to do. Just follow the instructions.

http://www.lexusownersclub.co.uk/knowledge...id=152&c=11

[dan-ny]

Thanks again to everyone.

As a next step, I had a mechanic clean the MAF as decribed in the article. He also felt that I had change the knock sensors......another $700 damage.

So in summary.....all Oxygen sensors changed, Flexi Pipe replaced, Knock Sensors replaced and MAF cleaned. The check engine light was reset.........$1600 and 20 miles later.......the light comes back.

I head back to Autozone for the lates read out.........the same code cames back: P0171 -The PCM has determined that during testing, the fuel system for Bank1 was too lean (Bank 1 identifies the location of cylinder #1, while bank 2 idenfies the cylinders on the opposite bank)

Any help will be greatly appreciated.

[wwest]

Thanks for everyone's response and feedback. Here's the latest scoop......

After changing all the O2 sensors....

1) I had Meineke replace the Flxe pipe......a 180 buck hole.....in holiday season ! :-(

2) Removed the EFI fuse to rest the light

The light stayed off for 5 miles.....and you guessed it.........it came back. So I went to Autozone to get the latest reading. These are the two codes:

P0330 - Knock sensor condition

- a malfunction exists in electrical circuit for knock sensor2 (Bank2) (bank 1 identifies the location of cylinder #1, while bank2 identifies the cylinders on the opposite side)

P0171 - Fuel trim bank one condition

- the fuel system for bank 1 was too lean (Bank 1 identifies the location of cylinder #1, while bank2 identifies the cylinders on the opposite side)

Thoughts? Suggestions? I am now confused......and lost.

Thanks in advance.

You very likely have a partially plugged up injector on bank #1. The knock sensor code is simply the result of the bad injector(s...??), the mixture on that cylinder cannot be enriched enough to prevent knocking/pinging.