another blown HG

[sliEighty]

ok i will prolly get bashed for this but i searched and couldnt find my situation... ive noticed a lack of power in my sr swapped 240sx however i see no smoke coming from the exhaust but with weak power and poor idle it leads me to believe a headgasket problem... could it be due to a bad o2 sensor... i have no had time to compression test it which i will do tomorrow but i wanted to get another opinion

[Phlip]

Compression/leakdown are good ideas, as would be pressure testing the rest of the cooling and all that goodness too. Odd losses of power, leaking coolant and an erratic idle were my signs. Mine never "blew" per se, there was never any mixing of oil and coolant, but it has been replaced nonetheless.

[sliEighty]

so no chance that its the o2 sensor i just checked it and there seems to be a wire that is cut loose... and when you replaced it was there a noticed difference