Skip the auto shop - Our mechanics make house calls

Q: Truck is running rough engine light. Keep call code

asked by on

Truck running rough tune it up code keep coming up mis fire 2 and 8. Smell coming out tail pipe like. Rotten eggs on 2001 dodge ram 1500 dont. Know if A C I nd to be change and. TB nd to be clean or cat is going or fuel pump with fuel filter nd ro be change please help thanks

My car has 137798 miles.
My car has an automatic transmission.

A: The rotten egg smell out your tail pipe is ...

The rotten egg smell out your tail pipe is the catalytic converter working to hard. It is doing this because raw unburned fuel is being pumped into it. This can damage it. If your Check Engine Light is flashing, this means there is a danger of the catalytic converter catching fire. So don’t drive it far.

With a tune-up you should have replaced the spark plug wires and the spark plugs. If it ran normally before you gave it a tune-up, I would first begin by checking the firing order. Even the best of us will mix up the spark plug wires from time to time. If the firing order is correct, I would suspect a broken spark plug. It is not uncommon for the porcelain to crack when we are tightening the spark plug. You should be using a spark plug socket. If you are not, you are lucky you didn’t break more.

If you have covered all that, then the next thing I would do is a compression check. If cylinders 2 and 8 have lower compression than the rest of the cylinders, you have leaking valves or piston rings.

Your A/C system, fuel pump, catalytic converter, fuel filter or throttle body won’t cause only two cylinders to misfire. It is possible you have injector problems, but this is unlikely with the rotten egg smell because this is an indication of unburned fuel being pumped into the exhaust.

If you’d like some assistance with this, consider YourMechanic, as one of our mobile experts can further diagnose your trouble codes and help you fix the problem accordingly.

Good luck!

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Burning smell coming from rear of van

Hi there, it sounds like your pads are rubbing against the rotor creating excess heat. Normally the pads release slightly off of rotor when the brakes are released and the wheels start moving. If the issue is still happening after...

Q: No fire motor turns over. Changed ignition coil crank shaft position sensor and idol air control sensor

Hello, thank you for writing in. The vehicle may be having one of several issues. If you have a slow crank, then the engine is not able to start because the starter is not going fast enough. Next you will...

Q: Toyota Corolla misfire on number two.

In many cases, misfires can be diagnosed by swapping components from the missing cylinder with the components of a functioning cylinder. Then you check the scanner to see if the misfire moves. It can be time consuming, but most auto...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...