hows it goin CL,im recently havin a little issue so far.on some mornings when i turn the car on,then start drivin it for about 3 minutes after,itll do a little sputter on around 1800rpm for a moment,then it wont do it anymore,also when i hop onto the freeway,i take it to 4200rpm with the overdrive on and itll also sputter and i give it more gas and itll struggle to pass that 4200 range,im hopin its just spark plugs not givin spark,please help,i bought the car about 2 months ago,the last owner said he had changed the fuel filter,spark plugs(ngk),royal purple oil,water pump and timing belt,please any help/advice?thnx,I recently also did a diagnostics check and threw codes 99(continous flashn code),13(r.p.m signal circuit open)25(lean exhaust)71(egr system problem,I mainly just wanna fix the sputterin issue,thnx