1996 Toyota 4Runner Oxygen Sensor

1996 TOYOTA 4RUNNER
8,000 MILES • 4 CYL • 2WD • MANUAL
Avatar
JOHNNYQUEST619
  • MEMBER
  • 2 POSTS
This engine has 8000 miles on a rebuilt motor. I replaced the Oxygen Sensor and the Check engine light still comes on. I hooked up the diagnostics to the car and was gettiing error code 171 and 3 cylinders are mis-firing. replaced the plugs, cap, and rotor. the problem still persist...

At idle the engine sputters and at freeway speeds it seems to be fine.

what could be the problem?
Mar 2, 2008 at 3:33 AM
Avatar
MASTERTECHTIM
  • ✓Experienced Mechanic
  • 4,750 POSTS
i would start by checking for a vacuum leak at the intake manifold area. do this by sprating carb cleaner at the intake and listen for change in rpm, then repair the leak. also you can do a compression test on 3 cyl and make sure its not a valve sticking. let us know
Mar 2, 2008 at 3:35 AM
Avatar
JOHNNYQUEST619
  • MEMBER
  • 2 POSTS
Thanks for the great Tip. I checked the intake using the carb spray and the idle changed. I found that the mechanic broke the gasket when putting the engine together. We replaced the gasket and the check engine light went off and there was no need to purchase the O2 Synsor. The engine had been running the the intake leak for a year. Could the leak cause damae to the engine?

This site is great, if i was directed here first i would have saved a couple of hundred $$$.

Thanks again...
Mar 28, 2008 at 5:57 AM
Avatar
MASTERTECHTIM
  • ✓Experienced Mechanic
  • 4,750 POSTS
no damage caused by this. thats great to hear.
Mar 28, 2008 at 8:18 AM
🔧 Tools & Auto Repair Parts
Find automotive tools, diagnostic equipment, and replacement parts for your next repair.
Shop on Amazon →
Paid affiliate link. As an Amazon Associate, we earn from qualifying purchases.
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle