check short term fuel trim and long term fuel trim

Once you find a scanner with live data capability, read long term fuel trim and short term fuel trim as well, they varies but over time should average to 0%. If they stay in large negative or large positive more then 10%, then you need to check O2 sensor B1S1,  MAF sensor and air leakage down stream from MAF. Something is cause the engine to run too lean or too rich which is very damaging over the long run.