J.Ho

Hello all. I just got a great deal on an 04 CE Convert with crazy low miles and I had some general questions for you experts please.

1. There have been some slight mods to my car. Aftermarket cam, magnaflow exhaust, carbon intake, bypassed O2 sensors... do these mods really make it that difficult to diagnose engine issues? I have a check engine light on (computer says just for emissions) and to hear the mechanic talk you'd think I had a Hendrick Motor in the thing. It left the shop after 2 days with the engine light still on. Truly that challenging or should I find another mechanic?

2. The previous owner installed tweeters on the waterfall and drilled holes and used glue to do it. I am trying to replace it and can't find a LeMans Blue waterfall anywhere. I plan on buying one off eBay and have a body shop paint to match (is there a best color for this? White?). My question... the black outlined corvette C5 emblems I see on eBay waterfalls look a little smaller than my chrome/silver emblem, and of course I want to use the original emblem.

I'm seeing things and they are indeed the same size emblems or am I right there is a size difference? BTW, no CE emblem on the waterfall, just a standard C5 logo in chrome. If someone could post the dimensions of their original black waterfall emblem from top flag corners and flag pole length I'd be greatly appreciative. This way I'll know if my emblem will rest properly in the molded space.

I'm sorry to come in here and ask a ton of questions off the bat, but this check engine light on everywhere I go is really starting to eat at me. Thank you in advance for any advice, suggestions, and info.

tcrote5516

Congrat's on the Vett! What's "crazy low" mileage?

1) No it's not that tricky but with bypassed O2 sensors the ECM would need to be programmed by someone that know's what they are doing to clear the code. I'm sure they tuned it but I know it's not so easy to trick the ECM into ignoring the lack of input from the O2's.

2) Color doesn't matter, it will need to be sanded down anyway to be prepped for paint. I'm not positive, but I don't believe different sized emblems were used at any point in the C5 run.

65GGvert

I don't have the link available right now, but someone can post it for you. With the C5 you can pull all the codes and display them via the driver's information center on the dash. Do that and see what code is causing the check engine light.
Could someone post the link for him?

tcrote5516

http://www.mediafire.com/view/?vdt6i4snee8bt4l

mclaugj

I just googled 2004 C5 Corvette DIC hit enter and make your selection. There are also instructions on how to pull them. Good Luck.

dadaroo

Here is how to pull the DIC trouble codes so we can see why the CEL light is on. View the video first and then read the writeup.


READING YOUR C5 Engine Diagnostic Trouble Codes (DTC)

This procedure should be carried out any time you experience a problem with your C5. Most inexpensive store bought aftermarket code readers will ONLY read power train DTC’s. Reading the DTC’s with the C5 built in code reader will allow you to read ALL the modules in the vehicle.

The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold the OPTIONS button
4) While holding OPTIONS, press FUEL button four times within a 10 -second period.

Initially, the on-board diagnostics go into an Automatic Mode which will cycle through each module and shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each module. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.

There are two types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes. More likely it's an indication of an intermittent malfunction.

Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.

Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles. There are a few body module DTC’s that if set will prevent the module from operating properly. Once the DTC is cleared, the module will return to full function. This is not true for power train DTCs.

If you have never read and cleared your codes, there will probably be a lot of old history DTCs. It is recommended that you clear your codes and see if any come back during a driving cycle. Those are the ones that you need to concentrate on diagnosing.

Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5.

NOTE and a WARNING. You can read the DTCs while the engine is running. I pull mine up all the time while driving.
WARNING. Don’t become distracted while reading DTCs while your driving and cause an accident!!!!! Use common sense and drive safe.

These are some very good C5 Diagnostic Trouble Code (DTC) explanation web sites!!! They also explain how to read the DTCs

Here are some very good sites that explain what DTC mean:

http://www.gearchatter.com/viewtopic11755.php

http://www.obd-codes.com/trouble_cod...d-ii-codes.php

Make sure to include the H or C suffix when you post your DTCs!!

NOTE!!! Start the car and let it idle. Then take it for a drive and cause the problem to occur. When you return home pull the codes BEFORE you shut off the engine.


Do NOT discount the codes with the H following them. They can provide an audit trail for issues going on with the car. They ARE important in diagnosing problems.

Post ALL the codes that you pull with the engine running..........

Some codes go away WITHOUT setting an H code when you shut the engine off. I suspect you will have several codes that will show C or HC that do NOT show when the engine is turned off.

J.Ho

Thanks so much for all the responses. Crazy low is 14,500 miles. One owner, FL car, clear carfax. I'm not sure how many extra horses the mods give it, but it sure will get up and go.

Ok, I'll pull the codes and report back. Like I mentioned before, a Chevy dealer said emissions. I want to see for myself though and this will be a fun project and learning experience. Like tcrote said I'm sure they tuned it up, it's just tricking it to turn off the engine light.

73Corvette

Not sure 14k is Crazy low...but it is low. Crazy would be like 5 miles...

Glad you found it and it will be a fun ride...Congrats!
We have a 04 vert 6 spd .. is yours auto or manual?

You also have an RPO list on the inside lid of your glove gox that will tell you about the equipment on your car...

Some of the 04 cars had problems with gas leaks... 2004 Chevrolet Corvette
VIN 45110258 to 45125500 are the cars that were affected.

J.Ho

Hey 73, thank you. Dang 1400mi/yr isn't crazy low? Tough room :P

It is an automatic. The car is not without it's flaws but the 3 piece, body matching custom painted wheels really set this lowered Vette apart from the crowd. Once I get everything fixed how I like I think I'll be happy with my purchase.

73Corvette

Awesome...ours had 23k on it now has 30k we got it in August... absolutely love it... great cars. lets see some real PICS bro.

PhysicsDude55

A reputable performance Chevy/Corvette shop can get rid of the engine codes. Tuning software lets you disable engine codes. Chevy dealer doesn't know this and if they knew, they wouldn't tell you. Its fairly common to delete the cats and/or forward 02 sensor when installing longtube headers.

It'll be hard to find a Lemans Blue waterfall... it was a color only offered in '04 on CE models, and only 2,600 convertibles with that color were made. Your best bet will be to paint one like you said.

J.Ho

Very cool. Yeah I'll admit I didn't give Corvettes their deserved respect until I drove one. Dang they have some bite!! What is the fastest speed you've reached? I'd love to find a closed runway and have some fun.

Unless I can figure out how to post some pics from my phone, I'll post some pics next week when I get home.

J.Ho

That is what I expected, thank you. I just found out a good friend of mine's dad manages a Chevy service dept... I'll be calling him asap

73Corvette

[QUOTE=J.Ho;1589062913]Very cool. Yeah I'll admit I didn't give Corvettes their deserved respect until I drove one. Dang they have some bite!! What is the fastest speed you've reached? I'd love to find a closed runway and have some fun.

We live in wheat country and some of it is WIDE open...you can see for 10 miles...as you can see on my avatar, so I bumped 150 just to see how it felt...had plenty to go but that was good enough for me.

zeevette

You can also install O2 sims that just plug and play. (Assuming that's the issue)

PhysicsDude55

Calling the Chevy service dept in regards to the Lemans blue waterfall or the 02 sensor issue? Dealer does not have the ability to remedy the 02 sensor issue, it can only be done with aftermarket tuning software.

I was the same way.. I always liked Corvettes, but didn't really "get" them until I owned one. Its a different and more exhilarating experience than I anticipated.

A few weeks after I bought my C5(back when it was stock ), I took a friend for a ride and hit 140 within about a mile on a highway. They asked if I topped it out, I said no, I only topped out 4th gear.. still had a whole 'nother gear to go

SG Lou

Congrats on your "New"C5

As for the Check Engine Light, before i'd jump to any conclusions I would pull all of the codes. There are two types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. Make note if they are History or Current Codes and post them here so we can all see what you got going on !
An alternative is to, again, mark down all of the codes. clear them all and then drive the car for a few days and see what code reappears. That should give us all an idea of whats going on with your C5 .

J.Ho

[QUOTE=73Corvette;1589063018]Noticed your avatar immediately... that would be some fun roads. 150? Good lawd. And here I thought my 110 was opening it up.

J.Ho

Thank you, I'll research that too

J.Ho

Yeah, you guys trump me on top speed no doubt.

Ok cool on the mechanic info... guess I need to be on the lookout for a performance shop just in case.