Could an exhaust leak cause a P0300 code at idle?
Could an exhaust leak cause a P0300 code at idle? Trying to figure out this P0300 code. My tuner said it only occurs at idle. The dyno graph is smooth and #s are on par (318/330 at 5K unlocked). Ive had a bad opti, its not the opti. The opti is a new delco unit. Plugs are TR 55s, MSD wires, and the coil is a Duralast with maybe 3K miles on it. The O2s are Bosch with maybe 6K on them. As stated the miss only occurs at idle and only for a few seconds if i set off after not letting the car warm up. Its noticeable but idle is fairly stable, it surges about 40 rpm. My concern is with my y pipe. It fits horribly at the collectors, the band clamps are barely holding it on. Would air leak into the collector causing the O2s to go crazy at idle but be fine under load?
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Joined: Nov 2010
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Trying to figure out this P0300 code. My tuner said it only occurs at idle. The dyno graph is smooth and #s are on par (318/330 at 5K unlocked). Ive had a bad opti, its not the opti. The opti is a new delco unit. Plugs are TR 55s, MSD wires, and the coil is a Duralast with maybe 3K miles on it. The O2s are Bosch with maybe 6K on them. As stated the miss only occurs at idle and only for a few seconds if i set off after not letting the car warm up. Its noticeable but idle is fairly stable, it surges about 40 rpm. My concern is with my y pipe. It fits horribly at the collectors, the band clamps are barely holding it on. Would air leak into the collector causing the O2s to go crazy at idle but be fine under load?
With how close the O2's are to the collector with longtubes you better get those leaks fixed and have it tuned again. Tuning around an exhaust leak is a big no no. The misfire is most likely from running too rich and fouling the plugs. Once an NGK plug gets fouled it is junk so you might want to check those too.
