Rep Power: 0

Hello
First post and thanks for having me.

After sitting for 7 years, my 16-year-old wanted to try to resurrect our 05 Civic Ex 1.7 l. It will sometimes start cold, with a very rough idle, and then will not start unless you unplug the fuel pump and plug it in once it clears up enough to start. The car is undrivable if it runs at all.

The only codes are oxygen sensor and intake air temp. I have confirmed that the resistance on the temperature sensor is correct at multiple temperatures. Have not done anything with the oxygen sensor.

I have had a favorable compression test(avg 180) and the leak-down test is good. I have Spark and the timing has been confirmed. No intake or exhaust restrictions were found. I have new fuel and confirmed injectors are functioning and clean, It has new plugs.
I have looked for any signs of wiring damage and have come up empty. I have an icon t7 scanner so I imagine what I can do with it is limited but I have noticed that the engine's rpm reads in the scanner's data after a reset but I lose signal after a minute or so. The scanner seems to communicate well with ECM and both crank and cam sensors are good(physically back probed and read signal voltage while waving metal in proximity). The rpm gauge on the car is pegged as far as it can go.

I am at a loss at this point and could use some advice on anything I could check. Thanks in advance Dave

ed

 
Rep Power: 223

How many miles are on it? Did you replace the old gas? What are the actual fault codes you're seeing?

 
Rep Power: 0

thanks for replying
vehicle will run now. I had originally disconnected exhaust at the manifold and no luck. After replacing plugs and upstream o2 it started running with exhaust disconected.. Converter has been removed and confirmed clogged. Parts on order and I think we found the problem.

 
Rep Power: 223

Keep an eye out for a failing head gasket (very common on 7th gens), otherwise it should make a great first car for your son!