Check Engine Light Diagnostics in Detroit
A trouble code names the circuit that reported a fault, not the part you need to buy, and that distinction is where most wasted money goes. A P0420 does not mean you need a catalytic converter; it means the downstream oxygen sensor is not seeing the difference it expects, which can be an exhaust leak, a lazy sensor or a genuinely dead converter. We pull the codes, then use live data, freeze frame and a smoke machine where relevant to find which one it actually is.
Bring it in if you are seeing any of this
Not sure which of these it is? Call and describe it. Half the time we can tell you over the phone whether it needs looking at today or whether it can wait for the weekend.
4.5from 58 Google reviews
Read them on Google rather than taking our word for it.
- Check engine light steady on, or flashing while you drive
- The car failed a Michigan emissions or safety inspection
- Fuel economy that dropped off with no other change
- Hesitation on acceleration or a stumble at low speed
- The light came on right after a fill-up
What we actually do on this job
- Full code scan including manufacturer-specific and pending codes
- Freeze frame data showing the conditions when the fault set
- Live data on fuel trims, sensor readings and misfire counters
- Smoke testing for vacuum and evaporative leaks
- A written explanation of what failed and what it costs to fix
Turnaround. Most diagnostics are done the same day you drop off.
What the price depends on
We do not publish a flat price for this, because a number quoted before anyone has looked at the car is a guess. You get a real one after the diagnosis, and you approve it before any work starts.
- Whether the fault is present now or intermittent and has to be caught
- Electrical faults that need circuit tracing take longer than sensor faults
- Multiple stored codes from one underlying cause versus several problems
- Access to the failed component in that particular engine bay
Free full synthetic oil change on your first visit
New customers only, with a paid service. One per vehicle. Ask for it when you drop off.
Free towing with any service over $300
Local tow to our W Warren Ave shop. Applied to your invoice once the repair is approved.
Check Engine Light questions
What people ask us about check engine light
Is a free code read at a parts store the same as a diagnostic?
No, and the difference matters. A parts store reads the stored code and hands you a printout. A diagnostic uses that code as a starting point and then tests the circuit to find which component actually failed. The code is the symptom. Buying the part the code names is how people end up replacing three sensors and still having the light on.
My check engine light is flashing. Can I keep driving?
Stop driving it. A steady light means a fault is stored. A flashing light means an active misfire is dumping unburned fuel into the exhaust, and that destroys a catalytic converter in a matter of miles. Pull over safely and call us.
The light went off by itself. Is the problem gone?
The fault stopped repeating, but the code is still stored in memory and the readiness monitors will show it. Intermittent faults almost always come back, usually in worse weather. We can pull the history and tell you what set it even after the light clears.
Can you help with a failed Michigan emissions test?
Yes. We read what the test flagged, check readiness monitors and fix the underlying cause so the retest passes. Clearing codes right before a retest does not work, because the monitors have to complete a drive cycle before the system will report ready.
Tell us what it is doing
We will call you back with what it most likely is and what it takes to find out for certain. If it is faster to talk now, the number is right there.
(313) 253-030020142 W Warren Ave, Detroit, MI 48228. Closed Sunday.
Related work
Engine Repair
Knocks, ticks, overheating and oil loss. We find out whether it is a repair or a rebuild before you spend anything.
Electrical Repair
No-starts, dead batteries every morning, lights that dim. Electrical faults get traced, not guessed at.
Exhaust & Muffler
Rust takes exhaust systems apart in this climate. Most of it is a weld and a section, not a whole system.
Who we do this for
Check Engine Light for drivers across west Detroit and the communities on our side of the city line.
Need check engine light in Detroit?
Call and describe the symptom. We will tell you what it usually means and what it takes to be sure.