lillexrx

Hi,

I have 99 RX300 w/118,000 miles. Five months ago I had a coil pack changed and new spark plugs ($600)... But after 5 months I'm suddenly having the engine flashing, rough idle and getting the same code again... I'm taking it back to the dealership and hoping they will take care of it properly...

The question I have is, the last time they said I needed a "Flexpipe" - can someone tell me what this is, and what it does? I know they are going to tell me that I need to have this done. But it wouldn't be what is causing the same "Cylinder 5 Misfire" Code would it?

Please help...

Thanks!!

bob2200

I think this ought to be transferred to the RX300 forum. I believe the flexpipe is the flexible connector in the exhaust system that is subject to failure. This has been discussed in the past on the RX300 forum.

VVT-i

On your RX, they're probably talking about the front exhaust pipe/flexpipe/down pipe. They're recommend because you may have some exhaust leaks.

Lexmex

This is the piece that my colleagues bob2200 and VVT-i are referring to and is a known issue with early year RX300s due to it cracking. I had to weld this a few times until finally I did some exhaust work here.

RTIS250

iTrader: (9)

As said above, the flex pipe is an exhaust pipe that connects the front bank exhaust manifold to the rear bank. If it is cracked, it is possible to suck in outside oxygen and fool the O2 sensors, and give a oddly running engine. However, in my years, i havent seen anything like this happen on an RX. Yours may be bad, but i would look elsewhere for your misfire problem. I would be looking at a coil pack or fuel injector failure.

Lexmex

To zero in on the possible area of the misfire, cylinder 5 is the one circled in blue and the one next to it is cylinder 3. This is located underneath the intake manifold.

Lexmex

My uncle and I see the fuel injector problem with misfires a lot with vehicles down here and the bad quality of the gas. Good quality gas is something I really treasure from north of the border.

lillexrx

Thanks for all of the replies! I just had all of my spark plugs replaced and a new coil pack on cylinder 5...the dealership did this. Now five months later, the same thing again... They told me last time that my flexpipe was cracked and I know that they are going to tell me that I need another one when they see my car later today.

Is a flexpipe something that my car desperately needs right now? Can it harm it to drive it without repairing it? My gas mileage isn't great, I can't get above 20.7, maybe that is affecting it. Still, I just spent $600 on the plugs and coil pack, I'd rather wait a bit if I can.

Thanks for all replies again!

Lexmex

No, but one need not necessarily replace it. Below is the piece similar to what is used to replace a cracked flexpipe with. I don't know exactly how much a dealer would charge currently, but I remember some total costs up in the hundreds of dollars a few years back.

What I'd recommend instead is to have someone at a muffler shop or someone with an arc welder just go under there and weld it shut. What you see in my picture of the area a few posts back is the 'after' when my uncle had welded the piece shut.

Down here this particular piece below cost me about $80 USD or so from my recollection (not including labor) for its installation, but this was for another area of the exhaust that had a problem.

Lexmex

This is another close up shot of the welded area. This a shot from when we were doing a transfer case fluid drain.

lillexrx

Lexmex, you're fantastic! Thank you very much You're right I called a Toyota dealership and they want at least $550 to replace it... And I know a Lexus dealership would be at least $800-900. So, I'm going to do what you suggest and in the next month or so find a muffler shop that might be able to do it instead.

I appreciate all the photos, so very helpful!!

Lexmex

That's the figure I remember 5 and something in change...outrageous.

I'd fix it myself if I were closer (eventually planning to move to Florida).

lillexrx

Good luck with your move, Lexmex!!

Cheers!

crx378

i would go to muffler shop for sure