SPONSORED LINKS

1994 Toyota Pickup Trouble code 27 and now 21 and 27

Tiny
COISC29
  • MEMBER
  • 1994 TOYOTA PICKUP
1994 Toyota Pickup 4 cyl Manual 225, 00 miles

Check engine light on trouble code 27, replaced front o2 sensor, rear was replaced about 5 years ago, after replacing front sensor I now have 2 codes, 21 and 27; 21 = main oxygen sensor fault, 27 = sub- oxygen sensor signal or heater circuit fault. Would replacing rear sensor fix the problem ? Or do I need to do something else?
SPONSORED LINKS
Monday, September 6th, 2010 AT 12:53 PM

5 Replies

Tiny
DOCFIXIT
  • MECHANIC
  • 18,828 POSTS
Are you using OEM O2s or after market?
Was this
answer
helpful?
Yes
No
+1
Monday, September 6th, 2010 AT 1:20 PM
Tiny
COISC29
  • MEMBER
  • 3 POSTS
The 1 front sensor that I replaced was a Walker oxygen sensor (aftermarket).
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
+2
Wednesday, September 8th, 2010 AT 10:41 AM
Tiny
DOCFIXIT
  • MECHANIC
  • 18,828 POSTS
Did you have to cut wires and reconnect?
Was this
answer
helpful?
Yes
No
+2
Wednesday, September 8th, 2010 AT 3:14 PM
Tiny
COISC29
  • MEMBER
  • 3 POSTS
No the plug fit perfectly.
Was this
answer
helpful?
Yes
No
+1
Wednesday, September 8th, 2010 AT 10:12 PM
Tiny
DOCFIXIT
  • MECHANIC
  • 18,828 POSTS
Several things can cause codes
leak in air induction
spark plugs
injectors
fuel pressure
distributor
wiring see schematic


https://www.2carpros.com/forum/automotive_pictures/198357_Graphic_610.jpg

SPONSORED LINKS
Was this
answer
helpful?
Yes
No
+4
Thursday, September 9th, 2010 AT 10:12 AM

Please login or register to post a reply.

Related OBD1 Code 27 Content

VIEW MORE

Sponsored links