Forums on car modification are buzzing with discussions about skirting OBD-II emissions tests. Many enthusiasts and even regular drivers are curious if there are ways to bypass these tests, especially when modifications or malfunctions cause vehicles to fail despite seemingly running well. This article delves into a forum thread on carparteu.com where users discussed this very topic, exploring the methods, challenges, and ethical considerations around cheating OBD2 emissions tests.
One user, “alex,” initiated the conversation by expressing surprise at the apparent lack of readily available methods to cheat OBD-II emissions tests. He questioned why, given the resourceful nature of car tuners and the desperation of some to pass inspections, there wasn’t a black market for OBD-II hacks or replacement systems. He described the testing process in his area (St. Louis), where a simple code check via the OBD-II port determines pass or fail status. This sparked a debate and information sharing among forum members.
Grizz jokingly suggested a drastic, albeit impractical, method: removing the computer altogether and reverting to a carburetor.
Image depicting a carburetor intake system, a humorous suggestion for bypassing OBD2 systems by eliminating the computer.
While humorous, this highlights the fundamental issue: OBD2 systems are designed to monitor and report on emissions-related components.
Ranger50 then brought up the concept of “readiness monitors.” These monitors are crucial because simply clearing codes before a test isn’t enough. The vehicle’s computer runs a series of self-tests, and only when these monitors are in a “ready” state will the vehicle pass. Clearing codes resets these monitors, requiring a drive cycle to complete, and a vehicle will fail inspection if monitors are not ready.
xd pointed to a more accessible method: using smartphone apps like Torque, along with a Bluetooth OBD2 adapter. These tools can clear codes, which, while not a cheat in itself, is a basic step in attempting to manipulate the system.
mmosbey provided a link to Missouri’s vehicle emissions testing exemptions, highlighting that older vehicles without OBD systems are exempt. This suggests one “legal” workaround: driving a pre-OBD2 vehicle. The exemptions also cover newer vehicles for a period, low mileage vehicles, and vehicles with specific fuel types, offering legitimate ways to avoid testing in certain situations.
nderwater shared anecdotal knowledge of successful OBD2 cheating, emphasizing that methods and success depend on the specific codes causing the failure. This hinted at more nuanced approaches beyond simply clearing codes.
alfadriver raised an ethical question, questioning the motive behind wanting to cheat emissions tests. He suggested it might stem from a desire to intentionally pollute for performance gains, sparking a debate about the purpose of emissions testing and the responsibility of car enthusiasts.
nicksta43 voiced a common sentiment that emissions tests are a “joke” or “scam,” citing inconsistent test results at different locations. This reflects a distrust in the testing system and a justification for seeking ways to circumvent it.
patgizz described practical methods of physical modification to pass visual inspections and trick sensors. Gutting catalytic converters while using spark plug non-foulers to relocate the rear O2 sensor is a known tactic. The non-fouler trick aims to pull the O2 sensor out of the direct exhaust stream, making it read cleaner than actual emissions. Patgizz’s own issue with a dead OBD port led to a sniffer test failure, ultimately resulting in registering the vehicle as commercial to bypass testing altogether, highlighting another, albeit costly and potentially dishonest, workaround.
Ranger50 offered a troubleshooting tip for dead OBD2 ports in GM vehicles: checking the cigar lighter fuse. This simple fix can sometimes resolve OBD2 port issues, a useful piece of diagnostic information.
Travis_K questioned the practicality of cheating for issues like misfires or vacuum leaks, arguing it’s often easier to fix the underlying problem. This brings a dose of practicality to the discussion, suggesting cheating might be more relevant for specific, modification-related codes rather than general malfunctions.
JoeyM pointed out that aftermarket catalytic converters can offer performance gains while still being emissions-compliant, suggesting that performance and environmental responsibility aren’t always mutually exclusive.
Swank Force One and alex clarified that the discussion was primarily about codes triggered by modifications that improve performance but are not recognized as emissions-legal, bringing the focus back to the tuner and enthusiast perspective.
ProDarwin asked for examples of modifications that improve performance yet cause emissions codes, leading to alex and 92CelicaHalfTrac providing examples like aftermarket camshafts and modified ECUs. These examples highlight the core issue: modifications aimed at performance can sometimes conflict with emissions regulations, leading enthusiasts to seek ways to bypass testing.
The forum discussion reveals a spectrum of perspectives and approaches to the question of cheating OBD2 emissions tests. From humorous suggestions to practical tips and ethical debates, it underscores the ongoing tension between vehicle modification, performance enhancement, and environmental regulations. While the forum doesn’t explicitly endorse illegal activities, it serves as a platform for exploring the methods and motivations behind seeking ways to bypass OBD2 emissions testing.
