Several states now require regular (annual or biannual) emission tests. These tests have different names; the most common are inspection/maintenance (I/M), SMOG, or OBD-II emission testing. The tests may involve visual inspection of certain emission-control systems, measuring tailpipe emissions at specified engine speeds or as the vehicle runs on a dynamometer, or verifying the proper operation of the emission system on 1996 and newer vehicles with a scan tool. A poorly maintained emission system can cause the vehicle to fail these tests.

Call 60 Minute Tune right away if your vehicle is having any of the following symptoms.

• Missing Pulsation or jerking that changes with engine speed.
• Exhaust has a steady spitting sound at idle or low speed.
• Sometimes your vehicle may display symptoms like a foul smell.