99 Sahara has flashing check engine light while driving
- Thread starter Woodard_
- Start date
Scan it with an OBDII scanner and see wha codes it's throwing.
Report back once you get the codes. That's where we need to start with this.
Report back once you get the codes. That's where we need to start with this.
Since it's flashing you really should read the code before driving it any further. A steady CEL is much safer to drive. It's likely a severe misfire which can damage your catalytic converter. Do yourself a favor and get a cheap ODBII scan tool. Amazon has them for under $20.
ODBII Scan Tool
ODBII Scan Tool
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I know from recent experience that a blinking check engine light is an indication of the engine misfiring and causing potentially severe problems. Yours does not look like its steady blinking but kind of erratically flashing in no particular pattern. Not sure whats going on there, seems like something is shorting out.
X2 to getting an OBDII reader and seeing what that says and reporting back.
X2 to getting an OBDII reader and seeing what that says and reporting back.
That problem commonly indicates something is happening that could damage the catalytic converter, often the fuel mixture is simply way too rich from a bad upstream O2 sensor. The PCM will not often be able to spot a bad O2 sensor since it has no ability to check it against anything else.
Your '99 has just one upstream O2 sensor, I'd replace it with an NTK or NGK and see what happens. Do NOT use any other brand of O2 sensor, especially don't use a Bosch. Don't waste your $$$ replacing the downstream sensor on the catalytic converter, it has nothing to do with this problem. No guarantees but this is what I'd start with.
This is the correct upstream O2 sensor for your '99... NTK 23151
https://www.amazon.com/dp/B001PNCKV8/?tag=wranglerorg-20
Rockauto has it for less at https://www.rockauto.com/en/catalog...77,exhaust+&+emission,oxygen+(o2)+sensor,5132
Your '99 has just one upstream O2 sensor, I'd replace it with an NTK or NGK and see what happens. Do NOT use any other brand of O2 sensor, especially don't use a Bosch. Don't waste your $$$ replacing the downstream sensor on the catalytic converter, it has nothing to do with this problem. No guarantees but this is what I'd start with.
This is the correct upstream O2 sensor for your '99... NTK 23151
https://www.amazon.com/dp/B001PNCKV8/?tag=wranglerorg-20
Rockauto has it for less at https://www.rockauto.com/en/catalog...77,exhaust+&+emission,oxygen+(o2)+sensor,5132
Sorry for a late response but I’ve replaced my 02 sensor I’ve talked with some people at some auto parts stores near me and the mentioned replace my Speed sensors because it sound like to them that me Jeep was trying to shift when it didn’t need to.