Random Check Engine Light - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members

General Miata Chat A place to talk about anything Miata

LinkBack Thread Tools
Old 01-05-2009, 11:26 AM   #1
Junior Member
Thread Starter
iTrader: (6)
Join Date: Apr 2006
Posts: 259
Total Cats: 0
Default Random Check Engine Light

Been having some issues lately with the check engine light coming on while driving (usally longer distances 30+ mile on the hwy; sometimes in town but rarely). My first guess is the o2 sensor as the wire fell aganist the downpipe and melted so naturally the car would kick the light on after a while of seeing nothing. I've since replace the sensor with a new one (still a one wire; autozone bosch $15-$20) and extended new wire up to the CAS. Since the check engine light doesn't come on every drive but seems to randomly and stay on until the car is shut off and restarted.

Anyone have any idea? Possibly not the o2 sensor and something else? Possibly the wire used to replace the burn wire isn't good enough for the job?

Note: Car has a stock greddy kit with an intercooler and a bipes for some car background. Doubt any of that has to do with the issue but figure I would leave the info anyways.
danscreations is offline   Reply With Quote
Old 01-05-2009, 12:19 PM   #2
Elite Member
iTrader: (9)
Saml01's Avatar
Join Date: Jul 2007
Location: NYC
Posts: 5,730
Total Cats: 2

You dont have an OBD reader?

Check engine lights dont only come on because of faulty o2 sensors. It can be misfires, malfunctioning air meters, IAC valves, anything. **** they come on from running to rich as well.
Saml01 is offline   Reply With Quote
Old 01-05-2009, 12:28 PM   #3
Junior Member
iTrader: (2)
Join Date: Sep 2008
Location: Sandy, Utah
Posts: 175
Total Cats: 0

Since you're OBD1, you can just do the paper clip trick on your diagnostic box and it will tell you what code it is.

To do this, you have to jump the pin (sorry, can't remember which one) to ground and then turn the key to on position. The CEL will blink the code to you, and then you can search for that code online.
Cpt_Slow is offline   Reply With Quote
Old 01-05-2009, 01:28 PM   #4
Elite Member
iTrader: (12)
Join Date: Jan 2007
Location: Hermosa Beach, CA
Posts: 2,575
Total Cats: 11

Sometimes mine comes on randomly, but I think its because of running rich when cold. To tell you the truth I really dont care anymore, all the stock ecu controls is the fans, idle, and a/c anyway...
cardriverx is offline   Reply With Quote
Old 01-05-2009, 03:23 PM   #5
Boost Pope
iTrader: (8)
Joe Perez's Avatar
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,326
Total Cats: 1,925

Originally Posted by Cpt_Slow View Post
To do this, you have to jump the pin (sorry, can't remember which one) to ground and then turn the key to on position.
It's TEN. You jump that pin to ground, turn the key on, and count the blinks of the CEL to get the code. Here are the codes: Miata Computer Diagnostic Fault Codes
Joe Perez is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 59 Today 09:00 PM
Changing from 460cc to flow force 610cc in diypnp 90 Turbo MEGAsquirt 19 10-19-2015 04:23 PM
Expected intake temps on the track? tazswing Race Prep 20 10-03-2015 12:04 PM
Leaky Wilwoods mx592 Suspension, Brakes, Drivetrain 1 10-01-2015 01:45 AM

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -4. The time now is 09:47 PM.