Diagnostics
Diagnosis
Finding out what is actually wrong — before anyone spends money replacing parts that were never the problem.
A code tells you which circuit reported a problem. It does not tell you why. We treat diagnosis as its own job: reading live data, checking fuel and spark under load, testing sensors against what the engine is really doing, and separating the fault from the symptoms it caused.
We see a lot of vehicles that have already had three or four parts thrown at them. Often the original fault is simple and was never tested for. That is a frustrating way to spend money, and it is avoidable — the dyno also happens to be an excellent diagnostic tool, because it lets us reproduce a fault under load instead of hoping it appears on a test drive.
Detail
What is covered
- Check-engine lights Codes read, interpreted and tested to root cause rather than guessed at.
- Drivability faults Rough idle, hesitation, surging, stalling, hard starting and poor throttle response.
- Post-build gremlins Swaps and engine builds that never ran right after assembly.
- Under load Faults reproduced on the dyno at the rpm and load where they actually occur.
- Fuel and spark Pressure, delivery, injector behavior and ignition tested with data, not assumption.
- Honest answers If the problem is mechanical and not calibration, you will hear that first.
Questions
Diagnostics FAQs
My car has a code but drives fine. Do I still need diagnosis?
Usually yes. A stored code means something measured outside its expected range, and on a modified vehicle that is often the calibration compensating for hardware it was never told about. It is worth finding out which before it becomes a bigger problem.
Another shop replaced parts and it still runs badly. Can you help?
That is a large share of what we do. We start over with data instead of assumptions — which sometimes means the last three parts were unnecessary, and sometimes means one of them was installed incorrectly.
Can a tune fix my drivability problem?
Sometimes, and sometimes not. If the vehicle has a vacuum leak, a failing fuel pump or a mechanical issue, a tune only masks it — and it will come back. We diagnose first and tell you honestly which situation you are in.
Do you diagnose engine swaps and custom builds?
Yes. Swapped and one-off vehicles are our regular work, and they are exactly the cases where generic diagnostic procedures fall apart and real data matters.
Also available
Other services
Dyno Tuning
Custom calibration on our Dynojet chassis dyno with real load, real data and a printed graph.
Learn more →AnywhereRemote Tuning
Email-based custom tunes for street cars and trucks, built from your datalogs and revised until it is right.
Learn more →Self-serveDyno Rental
Rent our Dynojet by the hour. Bring your own tuner, or use ours as the operator.
Learn more →Second opinionTune Audit
Built or tuned somewhere else? We datalog the vehicle and tell you whether the calibration is safe and making what it should.
Learn more →RetailPerformance Parts
Authorized distributor for the hardware we tune — ordered, installed and calibrated under one roof.
Learn more →Ready for a tune written for your vehicle?
Tell us what is on the build and we will tell you what the session looks like.