Bad Idle And More - Up For A Challenge? 2000 Rx300

[Quikfix]

I went to get an inspection and found that I had codes: P0446, P0441, P0440 - Emission control system.

The funny thing is that I did not have a CEL. As a matter of fact, the CEL doesn't shine at all even at start up.

Has anyone heard of that problem?

Later in the week, I get more codes but no CEL. P0300, P0304, P0305, P0306, P1150. Then the rough idle starts and I am not able to get out of low gears.

A year ago, I put new injectors on 1,3,6. A year ago, I did an extensive clean on the IACV with carb cleaner and Qtips.

Items I have done now:

1. Cleaned MAF.

2. Spray throttle body in place and spray down into the IACV.

3. Switch coil from 6 and 2 to try to move the code.

4. Buy new plugs for 2,4,6 to see if this improves situation at all.

I drive it out and around and immediately have a stuffy, clogged feel to the drive. at a half mile, I get a lot of muffler, exhaust hissing. I pull over and find my cat glowing like lava. after letting it cool, I limp home. I now have very loud exhaust hissing noise.

In the trouble shooting, I kept clearing the codes and pulling new ones to check. One code mentions I might be running lean (?? lean?). I pull the throttle body and check it. I pull the IACV and find it is still very clean. All my hoses are hooked up. I swap my coil from 6 to 5. I pull codes after running for 10 minutes and find that my code moved from 5 to 6. I now have these:

P0300, P0306, P0301, P1150.

Need advice on the above. Also:

1. Did I wreck my exhaust manifolds?

2. How do I check for vacuum leaks?

3. Has anyone ever run down the EVAP system?

4. Could I have crossed a hose connect last year and have the wrong vacuum hose connected? (My set up on the EVAP and VSV matches my book diagram - Haynes)

5. Does any one have any information on what the air fuel sensor is, how you check it, and how can I look up more information on it? (This search doesn't let you hit air fuel sensor because 'air' is too small a word.)

At this point, my RX300 is not driveable. I think I am needing to have it towed. Looking for advice. Thanks.

BTW, I have read a ton of good entries on this site. I fixed my RX well last year with this site alone. You guys rock. Thanks.

[code58]

I went to get an inspection and found that I had codes: P0446, P0441, P0440 - Emission control system.

The funny thing is that I did not have a CEL. As a matter of fact, the CEL doesn't shine at all even at start up.

Has anyone heard of that problem?

Later in the week, I get more codes but no CEL. P0300, P0304, P0305, P0306, P1150. Then the rough idle starts and I am not able to get out of low gears.

A year ago, I put new injectors on 1,3,6. A year ago, I did an extensive clean on the IACV with carb cleaner and Qtips.

Items I have done now:

1. Cleaned MAF.

2. Spray throttle body in place and spray down into the IACV.

3. Switch coil from 6 and 2 to try to move the code.

4. Buy new plugs for 2,4,6 to see if this improves situation at all.

I drive it out and around and immediately have a stuffy, clogged feel to the drive. at a half mile, I get a lot of muffler, exhaust hissing. I pull over and find my cat glowing like lava. after letting it cool, I limp home. I now have very loud exhaust hissing noise.

In the trouble shooting, I kept clearing the codes and pulling new ones to check. One code mentions I might be running lean (?? lean?). I pull the throttle body and check it. I pull the IACV and find it is still very clean. All my hoses are hooked up. I swap my coil from 6 to 5. I pull codes after running for 10 minutes and find that my code moved from 5 to 6. I now have these:

P0300, P0306, P0301, P1150.

Need advice on the above. Also:

1. Did I wreck my exhaust manifolds?

2. How do I check for vacuum leaks?

3. Has anyone ever run down the EVAP system?

4. Could I have crossed a hose connect last year and have the wrong vacuum hose connected? (My set up on the EVAP and VSV matches my book diagram - Haynes)

5. Does any one have any information on what the air fuel sensor is, how you check it, and how can I look up more information on it? (This search doesn't let you hit air fuel sensor because 'air' is too small a word.)

At this point, my RX300 is not driveable. I think I am needing to have it towed. Looking for advice. Thanks.

BTW, I have read a ton of good entries on this site. I fixed my RX well last year with this site alone. You guys rock. Thanks.

Quickfix- Too many questions- I don't have time to answer them all, but I would suggest you go to www.obd-codes.com Type in Lexus in the box on the home page. On the page that takes you to (Google) click on #2 and it will take you to the Lexus specific OBDll code page. It's an excellent site with a ton of information, not just on that page, but roam the site, a lot of help there. It definitely sounds like you have a plugged catalytic convertor. Remember not to take every DTC too seriously. You have all kinds of DTC's popping up there and often have to clear all of them and them see what pops up to get a better handle on the situation. If it doesn't even run now, that's a little tough. If your CEL didn't even come on when you turn the key on, maybe the bulb is burned out or some other problem, but that light definitely has to come on when the key is turned on. Either the catalytic convertor is clogged or blocked from coming apart inside or the muffler is, check 'em both. Good Luck!

Edit: The P1150 code is the air/fuel ratio sensor, and that sensor is the front one. When you open your hood, look straight down and it will be screwed into the exhaust. Looks like a spark plug with 4 wires coming out of it and plugs in about 6-8 in. away.

[Quikfix]

Okay. Received the call from the mechanic.

Two coils are bad: 1 and 6.

A/F Sensors are bad on bank 1 and 2.

Replacement cost is $1200 with factory parts. (coils are $115. A/F sensors are $265.)

That is $760 in parts and $440 in labor.

Other bad news and the results of the muffler noise.

Apparently, bad coils dump so much fuel into the exhaust that the cat is now bad. The mechanic suspects that the pre-cats may be bad, too (not sure what the pre-cat is.)

Catalytic converter replacement cost is $2400. If pre-cats are bad, too, it is another $2000 to replace them.

So, overall bill would be $5600.

Any comments are welcomed. I am thinking I will probably chase the core trouble and have them fix the coils and A/F sensors unless there is a better way.

Is that the normal cost of Air Fuel Ratio Sensors?

Is there a more economical way to do the above?

[lenore]

I would start with the coils, that would cause the air fuel sensors to read bad....Cost on coils should be around $80 to $100...each.

http://www.trademotion.com/partlocator/ind...playCatalogid=0

[RX in NC]

Model year? Mileage?

I agree with Lenore - start with the coils and hope you get lucky....

If your RX300 is a 1999 or 2000 with a ton of miles on it, there's no way that I would dump $5,600 into a 10-year-old, rapidly-declining vehicle. If I couldn't get it driveable and able to pass inspection for less than $2,000, I'd be cutting my losses and moving on to something else....

Good luck to you....

[Bobk528]

Okay. Received the call from the mechanic.

Two coils are bad: 1 and 6.

A/F Sensors are bad on bank 1 and 2.

Replacement cost is $1200 with factory parts. (coils are $115. A/F sensors are $265.)

That is $760 in parts and $440 in labor.

Other bad news and the results of the muffler noise.

Apparently, bad coils dump so much fuel into the exhaust that the cat is now bad. The mechanic suspects that the pre-cats may be bad, too (not sure what the pre-cat is.)

Catalytic converter replacement cost is $2400. If pre-cats are bad, too, it is another $2000 to replace them.

So, overall bill would be $5600.

Any comments are welcomed. I am thinking I will probably chase the core trouble and have them fix the coils and A/F sensors unless there is a better way.

Is that the normal cost of Air Fuel Ratio Sensors?

Is there a more economical way to do the above?

I had a bad coil (no. 6), drove another car to the nearby Toyota dealership, purchased a coil at the parts counter for $99 with my AAA discount, drove back home and replaced it in about 5 to 7 minutes. I'm no weekend mechanic but I read a number of DIY threads on the Lexus RX forms and was able to quickly replace it.

[Quikfix]

I agree that could change the coils that are needed. I am kind of frustrated that that is what it was as this forum has many listings showing coils going bad. I just thought it might be something more major.

This is a 2000 RX300 with 154k miles.

I agree. Not worth pumping $5k+ into it.

Possibly, I could do this myself with $650 in parts (2 coils and 2 Air fuel ratio sensors.) Not sure how hard the air fuel sensors are to replace.

Does anyone know about the catalytic converters? I understand there are two upper and one lower. Could I possibly fit a universal catalytic on this? I understand the lower one is bad.

[lenore]

Go with the coils, see what happens, everything else might clear up. I have 163k miles and have (knock on wood) lost no coils.