djmojo21

Hey all! So I'm having extreme lack of power issues under 3500 RPMs (no power when giving it gas and the car shudders) since replacing my clutch/flywheel (bought through Z1 Motorsports) two weeks ago on my '04 350z. My mechanic and Z1 Motorsports are concurring that although my two rear O2 sensors have been in failure status since I bought my Z last summer, that they are likely the cause of my problem and not an improper clutch/flywheel installation.

That's fine. I'll play along and defer to the experts even though neither of them have yet given me a concrete reason why my issue began immediately after the clutch replacement.

I've done some research on this, but being a novice, I'm confused by the results and I need to get this right. My questions are these:

1) I am broke after dumping over $3,500 into repairs on this car since I bought it. I'm trying to be as fiscally conservative as possible. Z1 Motorsports has new OEM downstream O2 sensors for sale for $140 a piece. They recommended Denso if I don't want to pony up and pay $140 for each (Rock Auto has them for about $70 each). My mechanic is strongly recommending Motorsport's OEM product. What are your thoughts about going Denso vs. Z1 Motorsports OEM version? Is there a general consensus on the reliability of Denso parts? I don't want to frack with installing sensors that are going to fail.

2) Are there any other Nissan cars (besides Zs) that have compatible O2 sensors that I could pull parts from at a scrap yard? I've been told by my mechanic that I may also need a mass air flow sensor. I was at a local UPull location on IT business the other day and he happened to have a mass air flow sensor on his desk pulled from another Nissan car that looked identical to others I've seen on Amazon and Z1 Motorsports. I want to make sure I'm pulling parts from a compatible vehicle before buying an nonreturnable used part.

I appreciate any input you guys may have to my questions or any other recommendations! Cheers.

dkmura

iTrader: (64)

How many miles on your Z? Are there any codes you've pulled?

djmojo21

90+K miles. Mechanic pulled P1278 and P1279.

dkmura

iTrader: (64)

That's pretty low mileage to have such significant drivability issues. Are there any exhaust mods that could alter the equation? As for brands, there is no "OEM brand", Nissan buys 02 sensors from NGK or NG and whether you get them from Z1 or Rock Auto, they're the same (as long as you buy the same model).

RWDBajan

Denso is a quality OEM brand. They make parts for all major Japanese brands.


Your problem does not sound like downstream O2 sensors. I think you need a decent shop or a dealer service shop.