Hey guys I am pretty new to this forum, but have viewed before and it is helpful.I am 19 and this is my first Vette. I have a 2000 Chevrolet Corvette Convertible Automatic. I have been having some problems with the C5. First off it idles very rough, it feels and sounds as if it were cammed. Second when accelerating there is a major loss of power it lags a lot, even when cruising at highway speeds and I try to floor it gets maybe 10% of its power if that. The car is unable to go above 85 because it won't go anymore even with the pedal down ready for WOT. When driving, the RPMs seem high...going 50-60 the RPMs are between 2500-4000 and I know that it isn't normal specially for an auto. The car has been in the family for a while, but when they were trying to sell it I simply said no and got it..I mean come on it's a Vette the car ran fine before, but has been doing this for about 3-4 months now and have now freed up some time to look into this. Also the gas consumption is pretty bad. The codes that are popping is P0300(that one is every now and then) the one that always pop up are P0174, P0753, P01153, and one other I do not remember. I have tried clearing the codes but come back in about a minute or so. Btw I have removed my cats if that makes any difference, it was after the issue that I removed them. Also for the random misfire I have already replaced the plugs and wires but no difference...could it be that I have a air leak and running lean??? Any help is appreciated, thanks everyone!



Save the Wave!

 

I was just wondering for the misfire codes. You changed the plugs and wires. Did you change the coil packs at all? I think the code will tell you what cylinder is misfiring. If not you can take it to an auto store and they can hook up a scan tool to it and find out. Once you have it down to what cylinder is misfiring you can change that coil pack.

 

In case you didn't get a chance to look it up yet, here are what those codes mean so you can do some searches. I'm sure someone much more knowledgeable then me can help you out with troubleshooting.

P0174, Fuel Trim System Lean Bank 2
P0753 1-2 Shift Solenoid Circuit Electrical,
P1153 Heated Oxygen Sensor (HO2S) Insufficient Switching Bank 2 Sensor 1
P0300 Engine Misfire Detected

 

check ur col packs,u might have a bad one or two

 

I did not change any coil packs on the car...they had it hooked up, but was only showing up as a random misfire which was 2 weeks ago, and as of last week, my OBD II port stopped working for some reason so I am out of luck there...but I will have to look into the coil pack..is that the issue?

 

Will do! I just want to make sure that this is the problem!

 

I forgot to mention that I have also replaced the 1-2 shift solenoid, but nothing changed, as for the fuel trim system lean bank 2 i was told before that it might be an air leak(vacuum leak) I just don't want to keep going back and forth and spending money where it doesn't need to be spent...this is tricky it might be the coil packs as said before though....

 

Someone will need to chime in on how to test the coil packs without use of a scan tool.
I understand not wanting to throw money at it without knowing if it will help.
For your P1153 Heated Oxygen Sensor (HO2S) Insufficient Switching Bank 2 Sensor 1 code
I think that's one of the Oxygen Sensors in the front. They are pretty easy to change and are about $40-60 at an auto store.

Do some searches on here and you will get some good results on your codes and how to troubleshoot them without spending any money.
Here is a good thread on the p0174 code.

http://forums.corvetteforum.com/c5-t...and-p0174.html

 

I would think a dead coil would cause all of those errors. Look at the plugs, on the pass side. I'd expect one of them to possibly be wet. Too bad you didn't look closely at them when you took them out.
I'd also do a compression check.
How many miles on the car?
Ron

 

The new plugs were installed not too long ago, and the problem with the old ones were that they weren't properly installed by the previous mechanic, but these new ones improved things by maybe 5% still running bad, and ok so more than likely it will be coils, huh? I was going to get a few compression tests done on the car, but they couldn't log their computer into the OBD II since it is dead...do you need the port to run the tests? As for mileage on the car...it is at about 177,000 give or take some...quite a few eh lol

 

If you have a bad 02 sensor, it will dump a lot of fuel trying to make the pcm happy. The 02 sensor should go rich lean rich lean so on so on. I'd change the 02 sensor on the passenger side front position before anything else. If you have removed the cats and still have the rear 02 sensors you will still get a ses light and codes untill you address that problem. The 02 sensor took a crap on my 05 chevy truck this winter and did the same thing. I used a Bosch 02 sensor and all was good. The coils can't do their job if you're flooding the engine with fuel.

 

Here's a link to the coil test
http://forums.corvetteforum.com/c5-t...oil-packs.html
It's quick, easy and cheap! If all of them pass, clear the codes.
Test compression on all cylinders. If they pass.
Swap your primary o2's and see if the p0174 changes to a p0171, if so replace the o2 you pulled from bank one. If not, it's running lean.
Also, check for power between terminals 4 and16 on your dlc. 4 is ground, 16 is powered by fuse 29 ip fuse box. It always hot. This should solve your problem with the scanner since you did not post any u codes.
With the scanner, check your fuel trims. Both banks should be 0 +or- 10 total st and lt. Negative numbers means the ECM is pulling fuel. I expect you to see high numbers b2lt25 st 10-25. That's where the lean code comes from.
The trans will not behave properly if the engine is running that bad.
Post results.

 

Defective 02 can run your fuel trims to the moon on that side and kill that entire side of the car, making it run horribly and clog your cats eventually.
If it's fuel trims run up by a defective 02 causing the problem, unplugging the MAF will put it in open loop and it should run better.
No matter how old your plugs are, pull them and post pics up.
Number them as you pull them.

Where are you located? If you're relatively local to me, I'll look at the car for free.

 

what kind of wires did you use? the oem wires must click twice before they are on completely. there are a few posts on here that some aftermarket wire brands like MSD don't always click on securely and cause misfires.

 

I had an O2 sensor go while on a trip. By the time I got it home it was missing badly and ran terrible, low power, hesitation and stumbling. I replaced the O2 sensor and plugs and wires, did the wires cause I found 1 reading 6K ohms. Car runs fine now. O2s are easy unless your harness plug has been distorted due to heat. If so BOSCH makes one with wire connectors that you can use.

 

Alright so I will change the upstream 02 sensors now, that would also make a lot of sense, but could it also be bad sensors and bad coils? I am trying to get as much feedback as I can and then sum it all up to just make one trip to get everything fixed

 

Alright thanks for the link! I am having a compression test done soon...as for the U code...I had one a few months back U1016 loss of comm. with PCM I believe, but I cleared it and it never came back, I'll have the fuel trims checked too.

 

I see, but will unplugging the MAF cause anything else to pop up besides, errors trying to read it? I am taking it within a few weeks to get everything fixed on one go, so they will pull the plugs there again and I will post them...I am located in Houston, I see you're in Forney, I used to live not too far from there, I was near Royse City! I am actually headed up there tonight, but unfortunately I can't take the car on a 4 hour drive the way it is running now :/

 

Yeah we made sure they clicked properly, I have the OEM wires, but running NGK plugs

 

Sounds a lot like the way mine was running! I'll for sure have those replaced!