New exhaust on C5 and now it runs BAD. PLZ HLP
#1
New exhaust on C5 and now it runs BAD. PLZ HLP
I had a set of the ebay headers, high flow cats, and a bassani xpipe installed along with my Flowmaster catback that was already on the car. The sound is simply amazing, but the car runs like crap. If I get on it at all it backfires and falls flat. If I am more then 20% into it the car will pop when it shifts any gear. Try and go 50% or more and it will stumble and backfire horribly. I also installed a set of Taylor Thundervolt 50 wires with a new set of NGK TR55 plugs. Because I had a local shop do the install I bet the gaps were not double checked. My first thought was the wires so I am considering swapping back in the new OE's I have. Just because the wires are significantly bigger I can not see why it would mess with the car though. Also I read the O2's could have possibly been swapped but not sure what affect I would have. Note the car does not smoke and has not thrown a CEL??? Please help
Also note- I just went outside and pulled one of the new plugs. I confirmed that a set of NGK TR55's were installed. The one plug I pulled was also gapped at .55 I noticed that there are TR5 plugs gapped at .35 and the TR55's at .50 I wish they were checked before installing. could this be my issue. With less then 3 miles on these new plugs, they were already pretty white so I assume the car is way lean. I do have a Fuel pressure gauge and that was fine.
Car is a 00 C5 Coupe.
Also note- I just went outside and pulled one of the new plugs. I confirmed that a set of NGK TR55's were installed. The one plug I pulled was also gapped at .55 I noticed that there are TR5 plugs gapped at .35 and the TR55's at .50 I wish they were checked before installing. could this be my issue. With less then 3 miles on these new plugs, they were already pretty white so I assume the car is way lean. I do have a Fuel pressure gauge and that was fine.
Car is a 00 C5 Coupe.
#2
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What got screwed up?? Pull all of the plugs to see if the gaps are 0 on some.
Are the 02 sensors plugged in the exhaust. Start looking for wires that are not connected.
Are the 02 sensors plugged in the exhaust. Start looking for wires that are not connected.
#4
I know for a fact it is either ignition or the O2 swap but which. My plan was to initially swap the wires back to OE and check gap on ALL the plugs. Others seems to really think the O2's are swapped. How could that happen. I realize there are 4 but would they accidently be swapped left to right or front to back. If I remember correctly, the fronts would not reach the rear?
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i ran those wires fo along time it shouldnt be the wires... check to see if all the plugs wires are connected with the plugs correctly recheck your coil packs and recheck your o2 connections.
#10
Damn I checked everything and it all looks fine. I swapped back to the OE wires and it did not change. I then checked all my connections and they are all fine. Lastly I looked at the O2 sensors and there is no way they could have been crossed. Without O2 extensions they would NEVER reach. I am stuck. I also got no codes in my DIC. All were History and none current.
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Originally Posted by teddyca
I looked at that and it seemsed loose but why would that affect the car? whouldn't that just be the brakes or could I have a vacumn issue from it.
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Are the O2 plugged into the front O2 ports? The rear O2 only confirm that the cats are working properly. The front O2 sensors control the fuel mixture. Normally the O2s get crossed because they are in the headers at an angle and you have to cross the wires over to get back to the side they control.
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Did you check the ECT sensor ? The car will run like crap if the PCM can't tell what the coolant temp is, and the sensor is right by the driver side header and commonly gets broken during header installs...
Just a thought.
Rob (Bad30th)
Just a thought.
Rob (Bad30th)
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It screws into the front of the driver side head, right by #1 exhaust primary.
The factory temp gauge, although slow to respond should jerk around when the car stumbles. If it only does it under load and runs fine the rest of the time it's probably not this sensor, but thought it would be worth mentioning.
The EFILive will be able to scan the coolant temp and it will show if it's way off.
It may or may not throw a code right away. My friend's Camaro didn't when his ECT sensor wiring got damaged, but my HPT scanner showed it was like -30 degrees outside, heh. His factory temp gauge did jump when the car stumbled.
Rob (Bad30th)
The factory temp gauge, although slow to respond should jerk around when the car stumbles. If it only does it under load and runs fine the rest of the time it's probably not this sensor, but thought it would be worth mentioning.
The EFILive will be able to scan the coolant temp and it will show if it's way off.
It may or may not throw a code right away. My friend's Camaro didn't when his ECT sensor wiring got damaged, but my HPT scanner showed it was like -30 degrees outside, heh. His factory temp gauge did jump when the car stumbled.
Rob (Bad30th)
#19
Great I will look at that. To be honost I really never checked to see it jump around, but as it ran like **** I made a point to continue to look over all the gauges in the car. I hope this sensor is just unplugged. I don't want to know what some of this crap costs. Leaving work in about 45 minutes to tackle the job.