Car not running right at high rpm's

[Njgunslinger]

Ok, weird issue, 2002 camaro SS, stock. Car was running perfect, car sat for a couple weeks, finally take it out today. Starts up fine, drives fine until I get on it, hit 4500-5000RPM range and the car just doesn't want to go, almost likes its choked. And at the same time, I hear a rattling noise coming from the drive side, engine bay area, and the Service engine light starts blinking. I get off it, drive fine at the lower rpm range, doesnt make the rattling noise and the service engine eventually stops blinking and goes away.
Oil pressue is fine, car is not over heating.
I bought some octane booster, filled it up with super, drove it around for a little bit, same thing happening.

Anyone ever experience, have any ideas?

Thanks

[Njgunslinger]

So Car has 29K original miles...

Spark Plugs?
Fuel Pump?
Pushrod?
valve spring?
F

[WildBillyT]

Shot in the dark- Possibly a misfire that's clearing. Check the plugs and wires. Maybe you cooked a wire on a header?

[Njgunslinger]

dont see a burnt wire.. but we'll start simple and change the fuel filter.

[SuperSweet]

the fuel filter isnt going to fix it...the SES light blinks due to misfire. have the code checked out to see what cylinder it is and go from there...odds are it is a bad wire or the coil is failing

[sweetbmxrider]

definitely scan the computer and its definitely a misfire. the CEL blinks when you are having a severe misfire.

[NJ346]

Make sure the plug that connects the coil racks are plugged in securely. Also it wouldn't hurt to pull the valvecovers and take a look at everything~30 mins taking your time.

[Njgunslinger]

P0171 - Car is running lean

[sweetbmxrider]

thats what i figured. do you have a scan tool that can view live data or freeze frame? you would want the car at operating temp in closed loop and record long term fuel trim, it should be above 23%. then check the o2's, they should be between 200-800mV. check for vacuum, emissions, air intake, and exhaust leaks in front of the o2's.

maybe you should figure out what the rattling noise is first, then get into the nitty gritty.

[Whiplash Performance]

Sounds something in the fueling isn't correct. So possibly a fuel filter, clogged injector.
Also check vac lines make sure there's no leaks. I've had that code before because a vac line came off.

[V]

ahhhh, i hope u find it and get it fixed soon.
..possibly fuel pressure drop..bad pump or maybe regulator
possible loose injector wiring connector or bad injector
or possible bad coil, plug, or wire.

ls1 fuel issues give me nightmares... i had raw fuel coming out my tailpipes... prior to the "incident"... injectors suck... so does shell putting diesel in ur car(they didnt even sell diesel)...::shivers::....

[Njgunslinger]

Im thinking loose wire or vac hose. Car was running perfect last time I drove, since then I put the hotchkis strut tower brace on, and may have hit something since it bends towards the back of the engine and I havent driven it since until yesterday..
Ill let you guys know, thanks for the feedback.

[Njgunslinger]

well havent time to do much, but did see a vacuum line off, so put that back on, but still misfiring.

[enRo]

Dealt with something like this last week. Check the O2 sensors and the wires that go to them.

[SuperSweet]

p0171 refers to the bank 1 being lean..check the left side of the intake manifold with the carb cleaner while its running. If that passes then change the O2. My O2 went bad a couple weeks ago and gave me a HORRIBLE misfire...one that I've never seen an O2 cause before.

If your not coming up with a specific cyl. misfire than its probably not an injector, but could still be fuel related.

[Njgunslinger]

Yeah its coming up with Random misfire code now. The fuel filter was just changed, same problem. We'll check the o2 sensors.

[sweetbmxrider]

did the random misfire set before or after the fuel filter was changed?

it should store the data when the misfire set. i would look at the data stream and see which cylinders are misfiring as well.

[Njgunslinger]

Well after all has been said and done, it was due to a bad Cat. The cat started rattling really bad and after revving it for a little bit, parts of it started coming out the tailpipe...Now car runs great.. :) And the cats are still under warranty, 8 years on it. So the dealer will replace it for free...Nice

[sweetbmxrider]

hahaha ahhh good stuff!

[1984camaroz28]

glad to see you found it. the best part is its a free fix :)

[Njgunslinger]

yeah, thanks for your advice though, I appreciate it. I need to bring the TA up to you one day. I think Im going to have hanlon rebuild/upgrade the tranny. It's tired, doesnt shift as well as it used to. :)


Thanks for everyone putting their thoughts in...definitely helps.

[1984camaroz28]

same give me a call when ur ready....