RX - 1st Gen (1999-2003) Discussion topics related to the 1999 -2003 RX300 models

Cel p0171 and p0420

Thread Tools
 
Search this Thread
 
Old 10-16-09, 09:05 AM
  #1  
JOHNBRAY11
Rookie
Thread Starter
 
JOHNBRAY11's Avatar
 
Join Date: Feb 2007
Location: AZ
Posts: 98
Likes: 0
Received 2 Likes on 2 Posts
Default Cel p0171 and p0420

I got these codes yesterday and was wondering if anyone has any trouble shooting ideas to prevent auto shops and hopefully change what needs to be changed myself. I changed the rear O2 sensor about 2years ago. So not sure if the forward one would need to be changed. Any help would be greatly appreciated. This forum has always been a great help in the past. Thank you
Old 10-17-09, 04:23 AM
  #2  
Lexmex
Super Moderator
 
Lexmex's Avatar
 
Join Date: Apr 2004
Location: Miami, Florida
Posts: 17,238
Received 159 Likes on 136 Posts
Default

How long ago did this occur and have you ran through a full tank of gas yet since it first lit up?
Old 10-21-09, 06:31 PM
  #3  
JOHNBRAY11
Rookie
Thread Starter
 
JOHNBRAY11's Avatar
 
Join Date: Feb 2007
Location: AZ
Posts: 98
Likes: 0
Received 2 Likes on 2 Posts
Default Cel

I actually downloaded it and erased the code and it has not come back. So do you think if something was really wrong the light would keep coming back right?
Old 10-22-09, 09:07 AM
  #4  
Lexmex
Super Moderator
 
Lexmex's Avatar
 
Join Date: Apr 2004
Location: Miami, Florida
Posts: 17,238
Received 159 Likes on 136 Posts
Default

Originally Posted by JOHNBRAY11
I actually downloaded it and erased the code and it has not come back. So do you think if something was really wrong the light would keep coming back right?
Yes, if something was wrong, they'd come back on.
Old 10-27-09, 02:17 PM
  #5  
JOHNBRAY11
Rookie
Thread Starter
 
JOHNBRAY11's Avatar
 
Join Date: Feb 2007
Location: AZ
Posts: 98
Likes: 0
Received 2 Likes on 2 Posts
Default Cel

Well it did come back yesterday. It said 2 codes but when i downloaded it there was only the P0171. I had the harder of the 2 O2 sensors replaced 2 years ago. Should I change the other one or what should i replace? Thanks for any help.
Old 10-27-09, 04:34 PM
  #6  
TunedRX300
Lexus Champion
 
TunedRX300's Avatar
 
Join Date: Jan 2005
Location: CA
Posts: 2,447
Likes: 0
Received 8 Likes on 6 Posts
Default

If not seized, the front A/F sensor is pretty easy to replace, you can go to Autozone for the loaner tool. Soak the sensor with PB Blaster and wrench it off.
Old 10-27-09, 09:04 PM
  #7  
Lexmex
Super Moderator
 
Lexmex's Avatar
 
Join Date: Apr 2004
Location: Miami, Florida
Posts: 17,238
Received 159 Likes on 136 Posts
Default

Originally Posted by JOHNBRAY11
Well it did come back yesterday. It said 2 codes but when i downloaded it there was only the P0171. I had the harder of the 2 O2 sensors replaced 2 years ago. Should I change the other one or what should i replace? Thanks for any help.
Keep erasing the code for a bit, and see how often the code comes back on.
Old 10-28-09, 10:09 AM
  #8  
JOHNBRAY11
Rookie
Thread Starter
 
JOHNBRAY11's Avatar
 
Join Date: Feb 2007
Location: AZ
Posts: 98
Likes: 0
Received 2 Likes on 2 Posts
Default Cel

Thanks guys. I erased the code again and it takes about 30ish miles for the CEL to come back on. How hard is it to change AF sensor? Where can i get a AF sensor from cheaper then Lexus? Do you know of any DIY on this project. I was just wondering if this is the solution to this. Sorry for all the questions. Thanks all the help on this.
Old 10-28-09, 10:20 AM
  #9  
artbuc
Instructor
 
artbuc's Avatar
 
Join Date: Oct 2005
Location: pa
Posts: 1,023
Received 101 Likes on 76 Posts
Default

Originally Posted by JOHNBRAY11
Thanks guys. I erased the code again and it takes about 30ish miles for the CEL to come back on. How hard is it to change AF sensor? Where can i get a AF sensor from cheaper then Lexus? Do you know of any DIY on this project. I was just wondering if this is the solution to this. Sorry for all the questions. Thanks all the help on this.

Cheapest A/F sensor I've seen is amazon.com for $127 plus shipping.
Old 10-28-09, 05:16 PM
  #10  
JOHNBRAY11
Rookie
Thread Starter
 
JOHNBRAY11's Avatar
 
Join Date: Feb 2007
Location: AZ
Posts: 98
Likes: 0
Received 2 Likes on 2 Posts
Default Cel

I just cleaned MAF sensor. found s thread a guy did it and it fixed it. But what should my next option be to do?
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
5t341th
Maintenance
12
12-16-17 03:23 PM
OG Dada
Performance & Maintenance
40
02-10-15 02:47 PM
02Legend
GS - 2nd Gen (1998-2005)
18
10-12-14 09:24 AM
GRANYZ400
GS - 2nd Gen (1998-2005)
6
01-17-13 09:05 PM
ks78
LS - 3rd Gen (2001-2006)
2
11-29-11 04:51 PM



Quick Reply: Cel p0171 and p0420



All times are GMT -7. The time now is 12:26 PM.