Oxygen Sensors and check engine light - YotaTech Forums

Notices
95.5-2004 Tacomas & 96-2002 4Runners (Build-Up Section) Post your build-ups here

Oxygen Sensors and check engine light

Reply

Old 12-28-2017, 08:17 AM
  #1  
Registered User
Thread Starter
 
Join Date: Jan 2016
Location: Taxtario
Posts: 86
Thanks: 0
Thanked 0 Times in 0 Posts
Oxygen Sensors and check engine light

So hopefully the smog test is going to be over where I live with the next election...or I could just move across the road...or even better out west! Anyhow...and a lot of ifs here...if the Cats go and I elect not to replace them and just straight pipe them, or if I put on a header which doesn't have the port for the one sensor, what do I do with the disconnected sensors? Likely disconnecting them or leaving them connected but not in the exhaust will trigger a ' Check Engine' light and that light is very annoying to say the least! How will this affect engine operation (performance/milage, etc)

What do guys do that swap newer fuel injected engines into first gens? (Yah I know wrong forum!)
Old83@pincher is offline  
Reply With Quote
Old 12-28-2017, 08:39 AM
  #2  
Registered User
 
Join Date: Aug 2013
Location: Southern Arizona
Posts: 2,674
Thanks: 0
Thanked 5 Times in 5 Posts
You can't do without a functioning upper o2 sensor. The ECU absolutely requires it for fuel management. (This is the one that would require a bung in the header.)

The second O2 sensor that is behind the cat is only there to monitor cat efficiency for emissions requirements and it does NOT contribute to engine management.

You CAN do without that one, but I don't know how to turn the 'check engine' light out in its absence.
millball is offline  
Reply With Quote
Old 12-28-2017, 09:07 AM
  #3  
Registered User
iTrader: (4)
 
irab88's Avatar
 
Join Date: Jul 2010
Location: S. MD
Posts: 6,362
Thanked 1 Time in 1 Post
"I know it's the wrong forum, but I'll post anyway"

The above info is correct all the way. However, I highly recommend just putting in an aftermarket cat. They are generally smaller and more efficient, so the fumes will be cleaner. They also help with sound and backpressure.

The second O2 sensor isn't required, but it's nice to have. There are ways to emulate it.

If you're doing an engine swap, you should have some experience working with welding. If the exhaust doesn't have an O2 flange, add one. I re-used the old pipe just fine, with new hardware.

If you're going through all this trouble anyway, you can always just pull the light out of the socket if it's annoying
irab88 is offline  
Reply With Quote
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
colorado-yota
95.5-2004 Tacomas & 96-2002 4Runners
2
09-22-2013 07:18 AM
MorphiasX
The Classifieds GraveYard
2
03-17-2008 10:46 PM
aNUT
95.5-2004 Tacomas & 96-2002 4Runners
9
09-02-2005 06:45 AM
95.5-2004 Tacomas & 96-2002 4Runners
8
08-10-2005 09:41 AM
Ontario
95.5-2004 Tacomas & 96-2002 4Runners
2
03-25-2005 10:20 AM


Thread Tools
Search this Thread
Quick Reply: Oxygen Sensors and check engine light


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description: