Some ECM tuners allow you to keep your OEM ECM for switching when a Dealer visit is contemplated...for an additional fee of course.
Here is a copy of the Air Filter issue I referred to:
Generally, driveability issues and engine operation conditions can be diagnosed using standard SI procedures, diagnostic tables and diagnostic tools. However, there is the occasional condition that cannot be satisfactorily addressed or corrected this way.
In cases like these, consider whether the vehicle has been equipped with non-OEM components or service parts. Because these aftermarket components were not developed, engineered and tested along with the vehicle they are installed in, they may not perform in the same way as the OEM part that was replaced. Two such cases have recently been identified and are summarized here.
Misfire with No Apparent Cause
This information applies to:
2004-07 ION Redline
2005-07 Cobalt SS
with 2.0L Supercharged Engine (RPO LSJ).
2007-09 Solstice GXP and SKY Redline
2008-10 Cobalt SS and HHR SS
with 2.0L Turbocharged Engine (RPO LNF).
A vehicle may illuminate a MIL with DTCs P0300, P0301, P0302 or P0304. The root cause typically cannot be determined. The misfire condition usually occurs with extended idling and may be reduced or eliminated by raising the RPM slightly or inducing an engine load (such as the A/C).
Engineering has determined that aftermarket parts (such as a light-weight aluminum flywheel or accessory belt drive pulleys) can contribute to this issue. Whenever any portion of the rotating assembly is changed to an aftermarket component, there is a potential for this condition. When diagnosing a misfire DTC and no condition can be found following SI procedures, inspect for installed aftermarket components.
Driveability Issues Related to Aftermarket Air Filters
Bulletin #04-07-30-013B addresses driveablilty issues in all GM cars and trucks. Some owners may install an aftermarket reusable air filter into their vehicle and then experience driveability issues, automatic transmission shift issues and/or an illuminated SES light.
The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the following conditions may occur.
- Service Engine Soon (SES) light on
- Transmission shift conditions, slipping and damaged clutch(es) or band(s)
- Engine driveability conditions, poor acceleration from a stop, limited engine RPM range
To verify the condition, compare the MAF GPS reading with the reading of a like vehicle that has an OEM air box and filter under the same driving conditions.
If a vehicle is encountered with these conditions, check for a reusable aftermarket over-oiled air filter. If an aftermarket reusable air filter is used, inspect the MAF sensor element and the air induction hose for contamination of oil before making any warranty repairs.
DO NOT repair MAF sensors under warranty if concerns result from the use of an excessively/over-oiled aftermarket reusable air filter.
TIP: The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty.
TIP: Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, over-oiled air filter are not considered to be warrantable repair items.
The other extreme is the UNDER-oiled air filter, which can also cause driveability concerns. The typical oiled aftermarket air filter requires cleaning and re-oiling at regular intervals to maintain optimum filtering. Failure to do so eventually allows fine debris to pass through the filter. A buildup of debris on the MAF sensor reduces the sensor's ability to correctly detect airflow, leading to driveability concerns