Check engine, O2 sensor, and Air Intake

[jlb0716]

about a year or so ago I fabricated a cold/ram air intake with parts I purchased at autozone. since then my check engine light has been on and its because the engine is running lean at terminal 1, which is the O2 sensor before the cat.

has anyone else had this issue? Im trying to decide if i want to change my O2 sensor in effort to resolve this issue.

any similar events and what was done to fix this issue.

I have an 01 4x2 2.5L 5spd. Lifted 4 inches running 30x9.5xR15 BFG AT K/O

 

[modelageek]

why would you change your o2 sensor to resolve this

 

[v8318cid]

Verify your OBDII codes before chaning the sensor. If you don't have a code specific to the O2, that most-likely isn't your problem. If you changed your intake system, did you retain all the OEM MAF/MAP sensors that were present before the change? If not, that could be throwing off the computer with regards to amount of air flow going into the engine as well.

 

[jlb0716]

yea I kept all the stock sensors and such, had adapters to retain the factory sensors. I have had a few people run OBDII code readers and it reports that the system is running lean at bank 1 which is the first O2 sensor out of the exhaust, the one prior to the cat.

 

[v8318cid]

If you're getting that particular code, the O2 sensor has probably failed, or is grounding out. The sensor is probably reading 0 volts which is equivalent to a lean burn code. Either way, if the sensor hasn't been replaced before, or is more than 60k+ miles (or 90k kms) old, its probably prudent to replace it anyway. I had a 92 (older obviously but had the exact symptoms you're describing) with a failed O2 sensor that gave a lean burn code. Voltage was always 0 when probed. Replaced the sensor - problem solved. Of course, changing an 02 sensor with over 200k miles isn't the easiest thing in the world, but was worth the 5mpgs I got back in the long run.

 

[jlb0716]

fixed the issue by modifying my air intake and reinstalling the stock maf adapter back in line, and disconnected the battery and reset the computer. I have not had any issues since, and had it inspected and it passed all the tests.