brabbit

So I had my 1999 RX300 awd in the at the Toyota dealership for a check engine light... 3 codes popped up P0171 system too lean, P1133 Air fuel ratio sensor circuit response malfunction, and the P1155 air fuel ration sensor heater circuit malfunction. both codes deemed bank 1 sensor 1.

Upon inspection it was found that I have an exhaust leak in front of the rear o2 sensor, they quoted me at 1845.00 parts and labor telling me that the part where the leak is has a platnium area in it or something???!!!! and that part of the xhaust costs like 1400??

I'm a student so I don't have a lot of cash flow coming in until the summer... as far as performance i've noticed a little jerkiness after letting off the gas and also my display is reading like 9-12 miles on the highway going 60 when I used to get like 22-24.... PLease help thanks...
the claim is that in order to determine if the sensors are bad the xhaust leak must be repaired. Does anyone have a suggestions on what to do I mean do i go online and look for a new performance exhaust system or ??? what would you do... I wouldn't mind getting a little better performance seeing that I have to fix the leak, I thought I might get a performance exhaust also if anyone could quote me what I should be expecting to pay for something like this.

lexus114

That is true,I just went through this with my daughter`s Elantra. But definitely get another quote, that price is too high.

Carver

That's one of those dealer boat payment things. Get a second opinion from a muffler shop and price part on eBay.

brabbit

ok guys thanks for the info.

So as far as the part on online.. is there any website in particular and also does anyone know what section of muffler I'd need to get if the leak is in front of the rear o2 senso?????
I'll go to a muffler shop here in town but just was curious.

Also can someone better explain why a leak in the exhaust would cause those codes (as far as a mechanic explanation) is throwing the codes that they are. I really appreciate any comments.

carguy07

Is this leak in the exhaust manifold or after the manifold?

salimshah

Look at this for part number

https://www.clublexus.com/forums/rx-...-catalyst.html

Salim

MASSMINI

If you find the right exhaust shop some leaks can be fixed with inexpensive welding. I recently had a center pipe leak (directly upstream from the rear sensor) welded for $60. See this thread.

https://www.clublexus.com/forums/rx-...pipe-leak.html

bearbrew

Check for a leak at the flex connector (braided) or one of the flange gaskets. There may also be a crack in the joint where the two exhaust pipes come together. A leak at any of these locations can cause a code.

carguy07

I don't think you are going to get those codes if the leak is after the exhaust manifold. The air fuel sensors don't know what happens down stream.

maxSteel

'rear o2 sensor'? Is that the one after the rear catalytic converter? That would account for the 'platinum' comment. But the dealer price for the cat is outrageous.

The claim that the repair is needed before determining if the sensor is bad is ok. The sensor can be fooled by the leak.

Definitely get another opinion.

brabbit

Ok guys, I feel like the problem is narrowing down... I'm going to investigate the problem a little more myself... I'm not that good with car problems but you guys have gave me confidence to take a closer look in determining the exact problem, I'll see if I can some good pics and then I'll post them if and when I find the exact problem. I'll then explain the problem to the mufler shop and go from there.

Quick question tho Why would I be getting like 8-12 on mpg at highway speed, it almost seems like the gas is just guzzled down as well... when the code read lean?? Could someone explain this and don't worry I'm not driving it now until the problem is fixed... I also remember a almost stalling hurky jurky motion when letting off the gas pedal.

carguy07

Your gas mileage is shot because it is probably in "limp" mode. Limp mode is used when the computer is getting erratic info and decides to stop using the info from the sensors and just use a safe program for running things. For a car safe is pig rich, so you are running super rich now and burning tons of gas. I would try clearing the code and see how quick it comes back. From the codes and what you are describing, it sounds like you have a cracked exhaust manifold that is letting extra air into the system before the sensor which makes the sensor think the car is lean.

brabbit

to clarify the leak is in the center pipe... in front of the rear O2 sensor.
so... I got a sweet post from massmini who had it repaired by a weld... i"m going to hope for the best

brabbit

so did u see that post about the weld done on the center pipe??? My quote was for a center pipe which is apparantly a lot to buy???? cause like I said my quote was 1845

carguy07

Yes, it sounds like you have a leak that needs welded up, but I don't think that is the reason you are getting those codes. Try reseting the computer and see if it comes right back. If it does I would bet that you need a new air fuel sensor for the rear bank.