On my 87 GMC van, 350TBI engine, I'm getting a code 13, which, depending on which book I look in, is either low volt on O2, or unresponsive O2 sensor.
That's the only code I have. Since the Bosch OEM O2 sensor replacement is less than $20, I'm tempted just to replace it, but is there anything else that could cause that code? The engine seems to run great.
Thanks,
CJ